That system is now under direct threat.

The Office of Management and Budget (OMB) has proposed a new rule to regulate all federal grants, not just science, but housing, education, defense, NASA and everything in between, that would fundamentally change how research is conducted in the United States.

There have been a lot of fires in the past 16 months, and if everything is an emergency, nothing is an emergency. But this is a very big deal. These rules would strip away the independence that has kept science from becoming a political tool.

The good news is there’s still something we can all do.

How the grant system was designed to work

When I was a new faculty member, I was full of millions of ideas, so I sat down and wrote an NIH proposal. I worked on it for months and thought it was so good. Then I sent it to my mentor.

It came back covered in comments. Places where my reasoning wasn’t as airtight as I’d thought, methods that could be stronger, gaps in my thinking that I had been too close to the work to see. It stung, as honest feedback always does, but peer review almost always makes the work better. In fact, it’s the backbone of how American science has functioned for generations.

At NIH, submitted proposals go to a panel of scientists who have experience in the field. These are the people who can read research methods and spot their weaknesses, who understand when an experiment is designed well and when it isn’t. Applications are scored rigorously, and often only the top 3-20% of proposals receive funding. The people making funding decisions are required to justify them based on these reviews.

To be clear: this is not a perfect system, and good science still goes unfunded more often than any of us would like due to limited resources. There is also criticism that peer review may undervalue bold ideas that are risky but could have high payoffs.

But the peer review system is nonetheless a meaningful part of the grant selection process. While thoughtful and careful changes could improve the system, the changes being proposed by OMB will not make things better.

The rule that could change everything

Through this OMB proposal, the system that helps decide what gets funded is being dismantled.

There are many troubling elements buried in this proposal, but three provisions stand out in particular. Each would be damaging alone. Together, they would change what kind of science gets done in America, and who it serves.

1. Political appointees would decide which science gets funded, and peer review would be explicitly sidelined or ignored.

The guidelines your doctor follows, the standards that determine what’s in your air and water, the drugs that get approved for your family: all of it starts with a funding decision. Right now, that decision is made by scientists who can evaluate whether the work is actually sound and whether it could move the needle forward. Under this proposal, funding decisions could be made by political appointees.

The careful, expertise-driven review process that shapes grant funding would be effectively sidelined. That means that a poorly designed study could get funded simply because someone in a political office liked the sound of it, while rigorous, important work doesn’t get funded because it no longer aligns with the administration’s priorities. In other words, critical work that benefits all of us could now be missed just because it has become politically inconvenient.

2. Grants could be canceled at any point, without warning, in the middle of ongoing work.

Say your tax dollars have been paying for a cancer study for two years. The grant was awarded for five years, so the team is mid-experiment. There are three additional years’ worth of answers that could change how the disease is treated for hundreds of thousands of people. With this new rule, the federal government could cancel the remaining funding tomorrow, walk away from the commitment it made with your money, and have no legal obligation to finish what it started.

This is a huge waste of money. There are rarely other sources of funding for this work, which means the team, the graduate students, postdocs, and research staff who have dedicated years of their careers to this project could lose their jobs. Patients who have contributed their time to studies may not see it turn into useful learnings for others. Every hour of work already completed could result in nothing useful.

Science can take decades to get to tangible outcomes. It needs a stable funding system to flourish.

3. Researchers would have a harder time communicating their findings without pre-approval from the federal government.

There is a saying from Sir Mark Walport: “Science isn’t finished until it’s communicated.” Science is no use to anyone if it is kept locked away in the labs that produced the data.

The proposed rule could make communicating research findings harder in a number of ways:

• Make it harder for scientists to widely share their findings in scientific journals. Publication costs, including journal fees that allow for broad public access, could not be paid for by federal funds which is often how scientists pay these costs.

• Restrict researchers from engaging publicly about how their findings should inform policy or public health guidelines. This would restrict scientists from doing the work that transforms years of lab work into decisions that actually affect people’s lives.

• Make it harder for scientists to attend conferences. Conferences would now need to be approved by the federal agency at the time of grant award. This disadvantages conferences or publications that are not politically aligned. Conferences are a key way in which scientists learn about work happening in their field so they can collaborate and build on each other’s findings.

What good is science with a muzzle?

The long-term impact

These changes could (and hopefully would) be reversed under the next administration. But by then, damage has been done. Once projects are halted or denied funding by political appointees, people leave their science careers for other paths or even leave the country to do their amazing science elsewhere.

You cannot pause a scientific study the way you pause a subscription you decided isn’t useful anymore. You cannot freeze a research team that depends on salaries to feed their families, causing a scramble for replacement funding that, in most cases, simply does not exist. When the money stops, everything stops, and all the work in progress and its potential are lost.

Despite all of the language about reducing waste, fraud, and abuse, this new proposed rule increases the administrative burden tremendously.

Every researcher watching this unfold will make a rational decision: don’t start anything that will take a decade to finish. This includes not building a team around funding that could vanish, or asking the big questions that need patience and stability to answer. The most consequential science, the kind that produces the treatments and the breakthroughs that reach your doctor’s office twenty years from now, is exactly the science that would be abandoned first.

This is still a proposal, so we can all do something

Some worry this rule is already a done deal. But by law, OMB is required to open a public comment period. Those comments matter because they inform members of Congress, they can be used in litigation, and they create a public record.

So here’s what you can do:

1. Submit a public comment. The public comment period on this proposed change is open until July 13. Anyone can submit a comment, and OMB is required to respond to substantial ones. Each comment must be different to count as distinct; identical comments will be counted only once. Comment as an individual, not on behalf of your organization. Here’s a full resource to help you, with useful examples, but in general:

   1. Share a story about how science or federal funding has benefitted you or is involved in your work. Are you or someone you loved a cancer survivor? Do you know someone with Alzheimer’s? Have you received NIH/NSF or other federal funding? All of these can be stories you use to highlight why you care.

   2. Explain why you’re worried about these proposed changes. You can use the wording found here or in other resources to help you.

   3. Ask them to withdraw this proposed rule.

2. Contact your elected representatives. Congress allocates money to federal agencies to spend, and it has oversight of how that process works. You can let your representatives know this proposed change concerns you and ask them to intervene. There are levers they can push that can help at this moment.

3. Let others know why federal funding matters. This isn’t just about science, but ALL federal grants, including for education systems, defense projects, and more. The process, including the importance of federal funding, is invisible to many. We can all make it more visible by sharing how science benefits us and why we value it. You can also share this article, or any of the resources linked here, to help spread awareness!

Bottom line

We are quickly losing ground in scientific research in the U.S. More changes, like the proposed rule by OMB, would decimate our ability to conduct research here, leaving us all worse off: fewer treatments for pancreatic cancer, less research on pollution impacts, fewer answers for patients with rare disease, and more unaddressed health needs. The impact will be very real for all of us, regardless of where we stand politically.

Using our voices for science is more important than ever.

Love, LM

Big thanks to Dr. Megan Ranney for reading this over and providing brilliant insights, as always.

Dr. Liz Marnik, PhD, is Executive Director of The Evidence Collective at YLE and a science communicator and immunologist working at the intersection of public trust, science, and public health. You can find her on Substack, LinkedIn, Instagram and Threads.

Your Local Epidemiologist (YLE) comprises a team of experts, ranging from physicians to immunologists to epidemiologists to nutritionists, working together with one goal: to “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. The YLE suite of newsletters reaches over 475,000 people across more than 132 countries. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

The World Cup kicks off Thursday, pulling millions together in celebration, but where crowds gather, pathogens follow. We’re debuting a new section on the health signals worth watching. Also on the move: a parasitic, flesh-eating fly eradicated in the U.S. in 1966 has found its way back (yes, it’s as terrible as it sounds). And 48 million people are facing serious heat risk. Good news is in the mix, too.

Here’s what’s going on, and most importantly, what it means for you.

Health “weather” report

Ticks are still increasing, and all respiratory diseases are declining to very low levels.

Things are heating up

This week, 48 million people will face “major” heat risk, and 100,000 will face “extreme” heat risk.

When it comes to extreme heat, it’s not just about the temperature you see on your weather app. While 120 degrees in Phoenix isn’t great, 90 degrees in New York can be worse.

This is because the risk to your health is due to heat imbalance. That’s when your body produces more heat than it can release. Normally, sweat helps cool us down. But when it’s hot and humid, sweat doesn’t evaporate as easily. The air is already packed with moisture, making it harder for your body to cool itself and raising the risk of illness quickly.

What this means for you: The following people should take action when their area is “orange” or higher. Everyone else, start taking action in “red.”

• People taking medications that impair heat regulation: Certain drugs interfere with sweating, hydration, or heart function, and can even reduce your thirst sensation. Check out the list here.

• Older adults: Aging reduces the body’s ability to sweat and regulate temperature.

• Infants and children: Smaller bodies heat up faster, and young children may not recognize or communicate early symptoms. Kids with asthma are at high risk.

• People with chronic diseases: Underlying conditions like heart disease strain the body’s ability to cope with heat stress.

• Pregnant women: Pregnancy increases metabolic heat production, making it harder to stay cool. More here.

• Outdoor workers and athletes: Prolonged physical activity in hot environments increases internal heat production.

• People experiencing homelessness: Continuous exposure to heat, dehydration risk, and limited access to cooling or hydration increases vulnerability.

Check the HeatRisk tool to know when to avoid strenuous activity. Stay hydrated. Watch for signs and symptoms of heat stroke. Check your urine color.

Be smart with fans: Fans can help when it’s moderately hot by circulating air and helping sweat evaporate. But once temps climb above 90°F fans may actually blow more hot air onto you, increasing heat stress.

Healthy Cup: Let the games begin!

The World Cup officially kicks off Thursday! YLE is playing a key role at the national Health Security Operations Center, and each week, we’ll share what we’re seeing in the data for those heading to the games or simply curious about what happens when millions of people mix.

While we wait for the games to start, epidemiologists are watching signals at and around base camps and practice games this past week.

The risk remains low, but three signals are garnering attention for now:

• Measles continues to spread in all three host countries, with a significant ongoing outbreak in Mexico. Seven base camps and practice games are near outbreaks, and these teams and their fans will soon disperse to other locations for the tournament. Make sure you’re up to date on the MMR vaccine and protection.

• Norovirus (nausea, vomiting, diarrhea) is declining nationally, with one notable exception: a sharp increase in the South that’s unusual for this time of year and worth watching. This is very contagious, and hand sanitizer won’t work. Wash your hands with soap and water.

• On heat… There was significant public concern about FIFA banning water bottles, which could become a big deal for heat-related illnesses. But on Friday, FIFA clarified (or walked back) its policy, saying attendees are allowed one 20-ounce (591 mL) unopened, soft-plastic disposable bottle (think: a bottle from a vending machine). Drink up.

We will be back next week for more.

Spotlight: Screwworm. The fly has landed.

Five cases of New World screwworm have been confirmed in the U.S. Texas declared an emergency, and Canada immediately restricted livestock imports. This bug could quickly turn into a big deal, and scientists have long warned about its return (I am surprised it didn’t come sooner, to be honest).

I called arbovirologist Dr. Miguel Arturo Saldaña in Texas to help break it down.

Screw… what?

New World screwworm (NWS) is a parasitic fly that was fully eradicated from the U.S. in 1966. It lays eggs in the open wounds of warm-blooded animals. When the eggs hatch, NWS larvae burrow into living flesh. It’s exactly as bad as it sounds, and is fatal if untreated.

How did we keep it out?

Starting in the late 1950s, scientists used the Sterile Insect Technique (SIT): mass-producing sterile males and releasing them to outcompete wild males, collapsing the fly population. It works because female flies mate only once.

Eradication moved down country by country from the U.S through Mexico and Central America over decades, eventually pushing NWS all the way to the Darién Gap in Panama (a remote landbridge of dense, mountainous rainforest). The U.S. and Panama maintained a binational barrier there, dropping roughly 20 million sterilized flies across six flights per week. For decades, it held.

But, for the past few years, it’s been crawling back up, and now, as predicted, to the U.S.

Why is it back?

A combination of factors:

1. Cattle smuggling. NWS detections in Panama spiked from 25 cases per year to more than 6,500 in 2023, driven largely by cattle movement outside sterile fly zones.

2. U.S. federal funding cuts. In early 2025, roughly 15,000 USDA positions were eliminated, and a USAID-funded monitoring project was terminated. Warnings passed as the pest moved north through Mexico.

3. Loss of expertise. In many countries, veteran veterinary entomologists have retired without replacements, taking decades of specialized knowledge with them.

Why does this matter?

• NWS spreads fast. A single female lays 200 to 300 eggs per clutch every three to seven days, up to 15 clutches in her lifetime. Eggs hatch within 24 hours; larvae feed for up to 7 days.

• Human cases are rare and treatable when caught early. The most recent U.S. case was a traveler who returned from El Salvador last year and recovered. Pets can also be affected.

• The bigger concern is the food system. Health and the economy are tightly linked. A 1976 Texas outbreak, a spillover from Mexico, affected 1.8 million livestock. A comparable outbreak today could cost Texas alone $1.8 billion, with losses across NWS’s historic range potentially exceeding $10.6 billion per year, and over $100 billion in broader U.S. livestock economic activity is at stake.

How do we stop it?

Same as before: SIT. Mexico is refurbishing retired rearing facilities to resume sterile fly production by summer 2026. A new U.S. facility in Texas will produce up to 300 million sterile flies per week, though experts estimate 400 to 500 million will be needed for full eradication. Ramping to capacity could take 18 months to two years. Panama is sending SIT males to the U.S. in the meantime.

What this means for you

The biggest concern is livestock, particularly cattle. Here are some tips to keep them healthy. To everyone else, the beef you eat is still safe.

Stray dogs and wildlife are also at risk; pets can be exposed too, but really only in agricultural areas. Ensure pets are on flea & tick prevention from the FDA-approved list, as products containing afoxolaner (dogs) or esafoxolaner (cats) can prevent NWS infection.

For people, risk is not uniform. Agricultural workers in the Southern states, particularly those with open wounds, sores, or skin breaks, are the most vulnerable, as flies are attracted to any open wound.

For everyone else, risk remains very low.

Good news

As always, ending on a lighter note:

• Melinda French Gates pledged $215 million to women’s health. Specifically, expanding contraceptive access, maternal care, and menopause research globally, pushing her total investment in women’s health past $600 million over the past two years.

• An experimental personalized skin cancer vaccine cut the risk of melanoma returning or causing death by 49% after five years when used in combination with immunotherapy. The vaccine is custom-built for each patient using genetic information from their own tumor, teaching the immune system to recognize and attack it. The vaccine still has a while to go through clinical trials, but this is welcome news given the increasing skin cancer rates.

• Inhaled insulin approved for kids with diabetes. The FDA approved inhaled insulin (Afrezza) for children ages 6 and older with diabetes. This is the first needle-free insulin option for pediatric patients in over 100 years. It’s a mealtime insulin delivered via a small portable inhaler, replacing the multiple daily injections kids currently need at meals. Pediatric patients and parents of younger children reported greater treatment satisfaction.

Bottom line

Lots of people and animals are moving, and with them, diseases. We’re keeping an eye on it all and will keep you informed.

Love, YLE

Your Local Epidemiologist (YLE) comprises a team of experts, ranging from physicians to immunologists to epidemiologists to nutritionists, working together with one goal: to “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. YLE suite of newsletters reaches over 475,000 people across more than 132 countries. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

I’ve sat in many classrooms as a student over the years. In none of them was I taught how to communicate in ways that best reach and meet the needs of the audience I was addressing. Particularly if that audience wasn’t scientists.

I learned through failures and experience, and by seeking out guidance where I could find it. But it shouldn’t be this hard.

It’s time to change this for our entire field. It’s time to go beyond the communications team at our institutions. Every scientist and community organization should know how to “translate” science to their community. And sure, some of us will remain in the lab, but some brilliance needs to be unleashed so more science can reach people, and more people can reach science.

The Evidence Collective recently provided data communication training, and not only was it insanely fun, but also, for the first time, I sensed a deep hunger. It gave me hope: scientists are no longer just trying to figure out where we lost trust; now they want to do something.

Here’s a peek at some of the things we covered, and things you should consider when working to better engage your communities.

Read more

So what’s going on with sunscreen? I called Dr. Michelle Wong, an Australian chemist, to help highlight the scientific nuance in sunscreen discussions.

Here’s what we know about sunscreen, what we don’t know, and what it may (or may not) mean for you.

Is sunscreen effective against skin cancer?

Nuance is needed, but yes.

Mechanistically, sunscreen makes sense. UV exposure is the main cause of skin cancers, especially in lighter skin tones, and sunscreens reduce the UV that reaches the skin. In laboratory studies, sunscreen reduces DNA lesions that accumulate over time and eventually lead to cancer.

When we look at “real-world” studies among humans, though, there is mixed evidence of sunscreen’s effectiveness against cancer. Two meta-analyses that pooled all these studies found no effect. However, this is hard to measure as most people apply less sunscreen than is recommended.

If we pull out the most rigorous studies (randomized controlled trials, or RCTs) that followed people over a long period of time, there is a positive effect:

• A long-term Australian RCT (15+ years) found daily sunscreen use reduced squamous cell carcinoma by 40% and roughly halved new cases of melanoma a decade later. No reduction was seen in basal cell carcinomas. However, the limited number of melanomas makes this finding less clear.

• RCTs have also found that sunscreen use reduces pre-cancerous spots (actinic keratoses) and moles in children (a risk factor for melanoma later in life).

Is sunscreen effective against photoaging?

This is a clear yes. Evidence from many studies across diverse populations, including a large RCT, shows that sunscreen prevents signs of photoaging, such as wrinkles and pigmentation.

But DIY sunscreens don’t work well

The chance of you consistently getting sunscreen in your home kitchen is… not great. Scientists estimated the highest SPF achieved in DIY SPF is 6.

DIY sunscreens don’t work for two reasons:

1. Sunscreen developers use special grades of zinc oxide with very small particles, which absorb more UV. These powders are also often coated to improve dispersion, while DIY recipes usually specify “uncoated” powders.

2. Even with the right ingredients and equipment, sunscreen formulators must optimize the formula extensively to achieve consistently high SPF—sunscreens are considered one of the hardest products to create!

What about the risks to the environment, like reefs?

“Reef safe” is a marketing term; there is no official standard behind it.

The term arose from a deeply flawed 2015 study, which led to public pressure that resulted in bans on specific sunscreen ingredients, usually oxybenzone and octinoxate, in some places, such as Hawaii.

But, there’s no good evidence that sunscreen harms coral, except in laboratory experiments where coral is exposed to unrealistically high concentrations. In 2022, the National Academies convened many leading environmental scientists to review evidence on sunscreen’s environmental impacts and compile it into a 400-page report. They confirmed what leading coral scientists stated when the original 2015 study was published: the impacts of sunscreens pale in comparison to far more significant stressors, like warming weather.

Why does the U.S. have fewer sunscreen ingredients than other countries?

Long story short: animal testing.

Sunscreens are one of the most scrutinized products we put on our skin— they’re regulated as drugs in some regions (the U.S., Canada, Australia), and a special category of cosmetics in others (European Union, Japan, Korea).

Historically, getting a new sunscreen approved by the FDA required large-animal studies that include hundreds of animals and over a year of testing to assess actual tumor development.

In other regions like the EU and Australia, a broader range of evidence could be considered for ingredient approval, including smaller, shorter animal studies, in vitro testing, and “real-world” population data.

Since sunscreens are cosmetics in many parts of the world, their ingredients fell under cosmetic animal testing bans. These took effect before the FDA pathway tests could be conducted for the newer sunscreen ingredients, so U.S. approval was never pursued. This has led to a bustling gray market for imported sunscreens containing newer active ingredients—these can provide high protection while allowing for more lightweight, elegant textures. They’re also designed to be inherently safer and less allergenic, with structures that absorb even less through skin. (More on this below.)

The good news: in the U.S., H.R. 5371 passed in late 2025, enabling the FDA to consider broader evidence, such as historical safety data and non-animal testing methods, when evaluating the safety of sunscreen ingredients. In the coming months, bemotrizinol (bis-ethylhexyloxyphenol methoxyphenyl triazine, or BEMT) may be the first new sunscreen ingredient approved since 1999. It’s one of the most popular “chemical” sunscreen actives used outside of the U.S., providing broad protection against both UVB and UVA.

Hopefully, other sunscreen ingredients will follow!

What about ingredient safety?

Differing regulations around the world have also led to confusion around sunscreen safety.

While there are two types of sunscreen, most questions are about “chemical” sunscreens due to FDA whiplash.

Note: Chemical sunscreens (e.g., oxybenzone, avobenzone, octinoxate) are carbon-based and are usually dissolved in the sunscreen formula, while mineral sunscreens (zinc oxide, titanium dioxide) are inorganic and found as solid particles. Both types of sunscreen largely work by sitting on the skin's surface, where they absorb UV radiation and convert it into heat.

For a long time, the FDA’s official stance was that the amounts of “chemical” sunscreens absorbed into the bloodstream were too low to pose serious health risks (defined as a carcinogenic risk greater than 1 in 100,000 after a single dose). They were thus considered safe by default, and detailed safety studies weren’t required. However, new FDA studies in 2019 and 2020 found that blood levels were actually higher than previously thought.

Importantly, this didn’t mean sunscreens are unsafe, but the FDA has requested more data to confirm their safety. Originally, this meant new large-scale animal studies would be needed, which would jeopardize the use of these ingredients in countries with animal testing bans. The recent passage of H.R. 5371 allows alternative studies to be used by the FDA to confirm safety, bringing sunscreen regulation more in line with other regions (the exact details should be issued soon). While in this regulatory limbo, these sunscreen ingredients remain on the U.S. market.

Although this may sound scary, sunscreen safety assessments from other parts of the world are reassuring. The EU and Australia draw on a broader evidence base, and because studies from the 1990s had already flagged blood absorption of chemical sunscreens, that was factored into their safety assessments long ago. And, every ingredient commonly used in U.S. sunscreens has been reassessed in the EU or Australia within the past six years. All were deemed safe.

Why not just use mineral sunscreen?

For those who prefer the feel of mineral sunscreens or are sensitive to particular chemical sunscreens, these can be a great option. And given the seemingly uncertain risks associated with chemical sunscreens, mineral sunscreen may seem like a safer, more appealing alternative.

However, with mineral sunscreens, keep in mind a few things, too:

• Unscrupulous marketing. Australia’s TGA has recently warned that campaigns promoting zinc-based sunscreens “often present incomplete and alarmist narratives about sunscreen ingredients.”

• Feel and appearance: When applied properly, mineral sunscreens appear white on the skin and tend to feel heavier than chemical sunscreens.

• Underapplied: The heaviness and white cast mean they tend to be underapplied. This results in far lower protection and a higher likelihood of sunburn.

• “Hidden” boosters: Due to these drawbacks, there are often hidden “SPF boosters” in mineral sunscreens. These are modified versions of chemical sunscreens, but do not need to be listed as active ingredients and do not undergo the same approval or quality control processes. Although they are likely still very safe, they can be difficult for people with sunscreen allergies to spot.

• Mineral sunscreens are inherently less stable. The particles are much denser than the other ingredients, which means they tend to clump and settle, and small changes in the recipe can throw off the whole product. A recent example: the 2025 Australian sunscreen scandal, in which some zinc oxide sunscreens turned out to provide far less protection than labeled, triggering widespread recalls and a major overhaul of sunscreen regulations.

So what do we do?

The health policy holds strong: sunscreen’s known benefits outweigh the unclear risks, and there are pros and cons to both types of sunscreen actives. Ultimately, the best sunscreen is the one that you will use a lot, regularly.

Overall, keep in mind:

• There are far more similarities than differences between chemical and mineral sunscreens in terms of effectiveness and safety. The main differences are aesthetic.

• “Broad-spectrum” sunscreen is best. The SPF rating on American sunscreen bottles primarily indicates a sunscreen’s ability to block UVB rays, the most damaging type. Some sunscreens in the U.S. don’t cover UVA rays well. Sunscreens labeled “broad spectrum” have a better UVA/UVB protection balance.

• Adequate application is key. The reliability of SPF testing has been in the spotlight recently, with some regions proposing scrapping specific SPF numbers altogether. While SPF 30 will always let in twice as much UV as SPF 50, the differences become much smaller with adequate application: for an adult, aim for one teaspoon for each limb, one for the front of your body, one for your back, and one for your head.

• Vitamin D can still reach the skin. High SPF sunscreens are designed to filter out UVB rays, the exact type of rays needed to produce Vitamin D in our bodies. However, sunscreen doesn’t block all of these rays, and its application is uneven because humans are humans. Unless you are very diligent with daily sunscreen application, including in winter, it’s unlikely that sunscreen will affect your vitamin D status. We also get Vitamin D from food sources.

For sun protection, layers are the name of the game. Sunscreen should be thought of as your last line of defense against the sun.

Bottom line

Sunscreen can help fight skin cancer and prevent photoaging. The nuances can feel paralyzing, but ultimately, the best type of sunscreen is one that you will use a lot of, regularly.

Slip, slop, and slap.

Love, YLE and MW

Dr. Michelle Wong is an Australian chemist and fellow science educator who addresses the top sunscreen rumors circulating widely these days.

Your Local Epidemiologist (YLE) comprises a team of experts, ranging from physicians to immunologists to epidemiologists to nutritionists, working together with one goal: to “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. YLE suite of newsletters reaches over 475,000 people across more than 132 countries. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

This left plenty of room today for good news and a time to celebrate (quite literally, as you will see below) scientific advancements, which have become my favorite section of the newsletter.

Let’s dive in.

Disease weather report

Ticks are… increasing again

After a few unusually eventful weeks, ticks are still keeping us on a rollercoaster. Emergency room visits for tick bites dipped briefly, then rose significantly again. We haven’t hit a record-breaking peak, but the season is running earlier than usual, so the cumulative burden is mounting. If this pace continues, it’s shaping up to be a rough tick season overall.

Those in the Northeast are feeling the brunt of it, followed by the Midwest. Although ticks are really everywhere.

What this means for you: Enjoy the outdoors! But if you’re in a tick-prone area, take that extra minute to do a tick check. The most important thing is removing the tick properly (use fine-tipped tweezers, grab close to the skin, pull upward, no twisting, no Vaseline, no matches). Then watch for symptoms: fever, rash, fatigue, joint aches. If you find an attached tick and are in a high-risk area for Lyme disease, it’s worth calling your doctor if it was attached for more than 36 hours. Here is a YLE deep dive on ticks.

Common colds peaked

We are finally reaching a point where almost all respiratory viruses are on the decline. Common cold viruses appear to have peaked after a higher season than last year.

PIV (parainfluenza virus) is also nearing its peak, which is worth noting for a slightly different reason. Unlike the common cold, PIV is particularly significant for babies, as it is a leading cause of croup and bronchiolitis. As you can see in the graph below, it is less common, though.

What this means for you: If you’re sick, it’s likely the common cold. Rest and fluids really do help boost your immune system.

Measles keeps on ticking along

I haven’t given an update in a while. While the acceleration has slowed down, measles is still spreading. It’s basically endemic at this point: jumping from unvaccinated pocket to unvaccinated pocket.

In the U.S., there are three active outbreaks public health officials are paying attention to:

1. Utah is in its eleventh month with active community transmission.

2. Virginia is where my eyes are right now. The outbreak is still small (64 cases) but growing quickly, with 21 cases in the past week. The vaccination rate in the community (Buckingham County) is low (84.9%).

3. Pennsylvania outbreak with 38 cases (six new cases in the past week).

What this means for you: If you’re up to date on vaccines, you remain very well protected. If you have a child under 12 months old and are in/around these areas, they can get vaccinated early. Here are the top 10 questions on measles protection answered.

Spotlight: Covid-19 virus and vaccines

Every summer since Covid-19 arrived, we have had a wave. And lately, summer waves are larger than winter ones (but continue to decline in severity due to immunity). Here’s where things stand.

What’s the current Covid situation? Levels remain very, very low. There may be a slight increase in some areas if you squint closely at the data (like in Texas and Florida, and maybe the Midwest), but it’s not showing up across all metrics. In other words, we’re not in a wave yet.

The Cicada variant (BA.3.2) received some attention a few weeks ago but has been circulating for some time without making much of an impact. The growing variant is XFG, which is still a descendant of Omicron.

Should I get a spring vaccine? The recommendation stands: vulnerable individuals, particularly those over 65, should still get both a fall and spring vaccine. Year over year, vaccination continues to provide 50–60% additional protection for high-risk individuals compared to those who skip it. If you’ve been trying to time a shot before the next wave, that window may be approaching.

Will we have a Covid-19 vaccine this fall? Yes, I think so, but the path to get there will be bumpy.

Think of our annual respiratory vaccine rollout as a giant domino setup. When the first domino falls—usually in February—the rest follow in a smooth, synchronized sequence, ending with shots in arms by early fall.

Last week, external advisors to FDA met to recommend an updated strain for this fall’s vaccine and voted to use the XFG strain. This differs from the WHO’s recommendation (LP.8.1). Strain differences between the U.S. and WHO aren’t entirely unusual—the U.S. typically targets the closest-matching strain for precision, while the WHO prioritizes broader coverage to accommodate countries with less flexibility to update quickly. Immunologically, the U.S. approach makes more sense.

But now the subsequent dominoes in the process of getting a vaccine may start wobbling.

The next step would normally be an ACIP meeting, but there is currently no ACIP, which is unprecedented. Two possible pathways are now in play, and both may end up being used:

1. The standard federal pathway (blue below). Either an ACIP is chartered (a long shot), or the ACIP step is bypassed entirely, and the CDC director signs off on the vaccine independently.

2. An alternative pathway (purple below) was developed last year by external organizations in response to federal disarray. Many states have already decoupled from ACIP and are instead following guidance from professional bodies like the American Academy of Pediatrics and the Vaccine Integrity Project (VIP). VIP will be meeting soon to review the evidence, enabling professional organizations to issue their own recommendations, which will then prompt health systems and physicians to begin ordering vaccines.

   
   Key limitation: This pathway doesn’t resolve the issue of ordering and distributing vaccines purchased through federal programs, most notably Vaccines for Children.

What this means for you: If you’ve been trying to time your Covid-19 spring vaccine before a wave, that moment may be getting close, though it’s still unclear. As for fall, I’m confident vaccines will be available, but expect some confusion and uncertainty in the run-up. But they will be there.

Good news, and lots of it

1. Standing ovation for pancreatic cancer survival study. During a national cancer convention (ASCO) over the weekend, results from a Phase III clinical trial of a pancreatic cancer drug were announced, and the room erupted in applause. This is really rare, but it also signals the beauty of the discovery. What did scientists find? Patients taking a new, experimental drug lived nearly twice as long as patients offered standard chemotherapy. Daraxonrasib reduced the risk of death by 60% compared with chemotherapy. Pancreatic cancer is a devastating disease, with a low survival rate, and is really hard to target with drugs. While this isn’t on the market yet, there seems to be major hope on the horizon.

2. Major health insurers announced they will cover all vaccines at no cost through 2027, regardless of what ACIP, federal disarray, and ideological preferences say. This is incredibly abnormal, as they usually wait for federal guidance, but great news and, quite frankly, just the right thing to do.

3. Americans are increasingly treating mental health like physical health. This news is a little older, but worth celebrating as we close out mental health awareness month: More than one in three Americans said they planned to make a mental health-related resolution this year, with younger adults ages 18–34 leading the trend at 58%. Growing cultural normalization of mental health care is itself a public health win, as stigma has historically been a major barrier to treatment.

4. An obesity drug may not just “melt fat,” but also decrease inflammation that drives heart disease, joint pain, and diabetes. Lilly is testing a new drug called retatrutide, a weekly injection that targets three hormones for weight loss. In its latest clinical trial results, released this month, participants lost an average of 71 pounds over about a year and a half and also made significant improvements in markers of heart disease and overall inflammation. The addition of glucagon targeting helps the body to burn fuel, enabling greater weight loss and likely accounting for the additional benefits over earlier GLP-1 drugs. The drug isn’t approved yet, and more safety and effectiveness data are coming, but the early results are strong. If future trials hold up, this could become a single-shot treatment for obesity, diabetes, inflammation, and their related health problems all at once.

5. Global teamwork (without the U.S.) towards health. The 79th World Health Assembly—whose theme was “Reshaping global health: a shared responsibility”—ended with 193 member states (notably the U.S. is no longer a member) agreeing on 20 decisions and passing 13 resolutions on a variety of health issues, including stroke, liver disease, tuberculosis, antimicrobial resistance, diagnostic imaging, emergency care, precision medicine, and radiation.

6. Ebola patients were discharged from the hospital. Five patients were cured of the Bundibugyo Ebola virus: four left the treatment center today, and another had already returned home. As Helen Branswell, from STAT, noted, “communities can distrust treatment centers, because loved ones go in & often don't come out alive. Hopefully, word of survivals will encourage people to seek care rather than staying home. Improves their survival chances & lowers risk to family members.” Ebola can be defeated.

Bottom line

While ticks and common colds are brewing, the quieter week allows us to recognize the quiet science marching forward. This week brought results targeting the two leading killers of Americans, heart disease and cancer. That is always worth celebrating.

Love, YLE

Your Local Epidemiologist (YLE) comprises a team of experts, ranging from physicians to immunologists to epidemiologists to nutritionists, working together with one goal: to “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. YLE suite of newsletters reaches over 475,000 people across more than 132 countries. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

I try to keep Fridays reserved for paid YLE subscribers, and particularly the professionals and trusted messengers who are guiding households, communities, and patients. My goal is to help make your life a little easier.

Here are the top four questions we received this week to help you feel confident navigating what’s going on:

1. I’m traveling to [X] country in Africa. Should I cancel my plans? Dr. Emily Smith is supposed to go to Tanzania, so I called her, and together, we created a decision tree.

2. Do airport checks really work? And if not, what is being done?

3. What is the status of the Covid-19 vaccine?

4. What’s going on with the U.S. Preventive Services Task Force?

Read more

Here’s an attempt to keep you up to speed and, more importantly, what it means for you and your community.

But first, an announcement: World Cup

The World Cup starts in 15 days (not like anyone is counting down), and we are hanging TVs in the Health Security Operations Center. It’s going to be a gorgeous, chaotic celebration of basically every culture on earth. And it’s going to take a team effort—from communities to individuals, from public health to health care—to keep people healthy.

That’s where you come in.

If you’re going to the games or live within 30 miles of a stadium, we would love to hear from you. Sign up for a weekly survey here. Thanks to the more than 1,280 people who have already signed up…you will be hearing from us soon!!

Global disease “weather report”

Hantavirus: Two more cases

The global count of cruise ship passengers with hantavirus has now increased to 13 cases (11 confirmed), with three deaths. The two new cases are overseas and among people who were already quarantining:

1. A crew member in the Netherlands.

2. A Spanish national passenger who was quarantining at home tested positive through daily monitoring. They are now in a biocontainment unit.

In the U.S., everyone remains negative.

There may be more cases, given that the incubation period of hantavirus (the time from exposure to infection) is 45 days. But this week, we will reach a major milestone: the median incubation window is 18 days, and that will pass on May 29.

What this means for you: Your risk from this cruise ship outbreak remains essentially nil at this point.

Ebola rages on in Central Africa

Big thanks to Dr. Craig Spencer, a humanitarian physician who has treated and survived Ebola, for jumping in to provide the YLE community with an update. Craig, take it from here…

The combined confirmed and suspected Ebola cases in DRC are now more than 1,000. All signs are pointing to a very long and catastrophic outbreak in Central Africa:

1. This is a vast undercount. We know this because the test positivity rate is hovering around 50%, only 20% of contacts are being traced (and in some areas, no contacts at all), and more cases keep popping up with no known connection. This all points to widespread and undetected community transmission.

2. This is in only a week of detection. Compared to previous outbreaks, the growth is very fast, as the huge West Africa outbreak in 2016 was first detected at 49 cases and rose to 208 cases a month later. It took four months for that outbreak to reach the size of the current one in the DR Congo.

3. The cases are spread out across 16 health zones. There are now multiple epicenters, making containment very difficult.

Next door in Uganda, the case count is seven. While this number is low compared to DRC, a concerning development is that two health care workers recently tested positive with uncertain exposure histories. If they weren’t treating known Ebola cases, this means it’s spreading undetected in Uganda as well.

On the ground, backlash, including the burning of health centers, has emerged, a pattern seen in nearly every outbreak and rooted in deep community distrust. It often stems from outside actors working in communities without fully understanding or addressing local priorities. Affected populations may recognize the severity of Ebola while still holding other concerns as more pressing, such as where their loved ones are buried. Community trust is essential to an effective response, but difficult to build during an active emergency. It is best established long before a crisis begins.

U.S. priorities are made clear, and may backfire. The U.S. Administration has shown that its first priority is keeping Ebola out, with helping end the outbreak in the DRC a secondary concern. That's meant travel restrictions broader than anything we've imposed before — covering travelers from across the region, and reportedly some green card holders and permanent residents as well.

For example, just these past two days, news broke that high-risk American travelers will be subject to a mandatory quarantine in Kenya before they are allowed to return. If an American is infected, the U.S. government plans to send them to a hospital it is standing up from scratch in Kenya. (Currently, Americans who were in the area are allowed to return but are diverted to three airports—Houston, Atlanta, and DC—for further screening.) Past administrations have used travel notices and stepped-up screening; this goes much further.

At first blush, these strict precautions may sound prudent. But this approach could backfire in three ways:

1. Restrictions this blunt give people every reason to hide where they’ve been and whom they’ve been near — making the people we most need to find harder to track, not easier.

2. They also breed a false sense that this is someone else’s problem. But diseases are humbling. They find the small cracks in even the most impenetrable-seeming defenses.

3. Lives lost. There is no treatment for this Ebola strain, which means survival depends heavily on the quality of the health system. We have that system in the States, but we are choosing not to use it for infected Americans.

This is unbelievable and infuriating. (See a deeper dive from me here.)

The only real way to lower the risk to Americans — and everyone else — is to end the outbreak in the DRC and across the region.

What this means for you: If you have travel plans to this region, it’s time to cancel them. This is a high-risk situation in Central Africa, and CDC released a Level 4 Travel Advisory. There is also great uncertainty if and when the Administration will let you back in.

To the general public in the U.S., your risk remains very, very low right now.

U.S. disease “weather report”

Ticks: past peak season?

Good news, especially for people in the Northeast and Midwest: tick numbers continue to decline. Though we are at the peak of the season, this unusually early year is trending favorably.

Heat-related illnesses in the North

Heat risk is certainly not blanketing the entire country yet, but this week it will be moderate in the Midwest and the Southeast.

What this means for you: Be sure to check the CDC HeatRisk tool. A red day isn’t the best day for that soccer game for a kid with asthma, and a stretch of orange days is a great time to check on your elderly neighbor.

Common colds surging

As far as respiratory viruses go, the only thing really going around right now is the common cold. It is higher this year than last year, but should peak very soon before returning this fall.

Spotlight: Chemical plants

Over the weekend, YLE California covered the serious situation that unfolded around a chemical plant in Orange County, California. Thankfully, the worst-case scenario (a chemical explosion) was mitigated, but only through luck. The health implications in a densely populated area could have been catastrophic.

As the situation was winding down, another chemical explosion struck Washington State. This one was fatal. Health officials say the risk to surrounding residents from chemicals in the air and ground remains low, though the community deserves far greater clarity.

Clean air and clean water consistently rank as Americans’ top public health concerns — yet when chemical disasters strike, communities are too often met with reassurances rather than transparency and accountability. Residents near the 2023 East Palestine, Ohio train derailment, for example, are still waiting to understand the long-term impact on their health, with few clear answers.

What this means for you: Many are wondering if facilities processing potentially dangerous materials are in their neighborhoods. This interactive map allows you to enter your ZIP code and see all facilities monitored by the EPA, including any violations.

Good news

• Ebola vaccines and treatment for the Bundibugyo species are in development. Two vaccine platforms are being explored, at least one of which may be deployable in as little as 2 months. One vaccine is being developed by Oxford, and the other uses the same biotechnology as the FDA-approved Zaire species of Ebola. (It may provide cross-protection, but it’s unclear at this point.) On the treatment side, two promising monoclonal antibody cocktails are likely to be deployed, though doses are limited and logistical hurdles remain significant challenges. Anni over at The Biotech Tea had a great explainer about the Ebola vaccine gap, if you want to read more.

The Biotech Tea

The Ebola vaccine gap, reading vessel damage, & the Makary exit

🗝️ Paid subscribers get the Biotech Term of the Week at $30/year (~$2.50/month). I try to keep it intentionally accessible, but if cost is ever a barrier, send me a message. A few people asked about expensing your subscription, so I put together a short email template…

Read more

21 days ago · 10 likes · Annicka Evans, PhD

• Polycystic ovary syndrome (PCOS) has been officially renamed polyendocrine metabolic ovarian syndrome (PMOS), following more than a decade of debate and input from roughly 22,000 clinicians, researchers, and patients worldwide. This is good because the old name was medically misleading, leading to patients without visible cysts being dismissed or overlooked entirely. The WHO estimates that 70% of people with the condition remain undiagnosed. A more accurate name should improve recognition, reduce stigma, and ultimately help the millions of people living with this condition get diagnosed and treated sooner.

Poll

Bottom line

Public health situations are everywhere right now. Staying healthy takes public health professionals and systems working tirelessly behind the scenes and each of us showing up for our neighbors and communities.

Love, YLE

Big thanks to Ed Nirenberg for staying on top of the Ebola vaccines, Hannah Totte for all the figures, Dr. Craig Spencer for the Ebola insight, and Dr. Matt Willis for covering the chemical situation in CA.

Your Local Epidemiologist (YLE) comprises a team of experts, ranging from physicians to immunologists to epidemiologists to nutritionists, working together with one goal: to “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. YLE suite of newsletters reaches over 475,000 people across more than 132 countries. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

This made our most recent webinar incredibly special. We heard directly from four rockstars—our own Liz Marnik, Executive Director of The Evidence Collective, a program under YLE; Anna Culbertson; Kelsey Fox Bennett Boyd; and Kristin Oliver—who were raised unvaccinated and eventually changed their minds. (Liz shared more of her experience here in the NYT.)

Their stories show us how we can improve conversations with people who might be vaccine hesitant and, most importantly, foster empathy and understanding for the process of changing one’s mind.

Paid subscribers can access the full webinar recording above—I know many of you have been waiting for it!

Five key takeaways

1. Changing minds takes time. Nobody in this conversation went from having never been vaccinated to running to get vaccines overnight. Over time, small moments add up: a coach’s offhand comment, a college requirement, becoming a parent, a story from a friend. Plant seeds and trust they’ll grow.

2. Vaccine decisions play into identity. Whether to get vaccinated is tied to whom they trust and where they belong. People’s reasons for not getting vaccinated vary—like every other aspect of identity, there’s more heterogeneity here than we might expect. Acknowledging the identity piece, instead of treating this as a debate over facts, is a step toward meeting people where they are.

3. Close the language gap. Panelists consistently felt safest with people who could meet them on their terms. Being open to terms like wellness, “root cause,” and prevention makes a difference—in truth, these are things we all care about, and familiar language supports trust-building. So does being curious about how alternative medicine and holistic approaches may complement Western medicine.

4. Get genuinely curious about sources. We are exposed to information constantly, and our online environments make it easy to sound authoritative without vetted experience. Some people have had dismissive or harmful experiences with the medical system that understandably influence their perspectives today. Questions like “Where did you hear that? What made you trust that person? Can we listen to that podcast together?” show true curiosity. Asked without judgment, these questions signal that you’re interested in truly understanding, not in winning a debate.

5. You don’t have to be a doctor to be a trusted messenger. Every story in this conversation pointed to the same thing: the people who created cracks in the system that questioned vaccines were not physicians. They were coaches, friends, fellow parents, and people sharing their own stories of going from unvaccinated to vaccinated.

FAQs

Webinar participants asked fantastic questions, but we ran out of time to address them all live! Liz chose four to address here:

Read more

Ebola is often called the disease of compassion by experts like Dr. Craig Spencer. It spreads through direct contact with bodily fluids, which means it spreads when a family member tends to the sick, when a nurse stays at the bedside, or when a community gathers to bury their dead. In other words, it’s spread through acts of care.

But the phrase has been sitting differently lately because this outbreak is spreading not only through compassion but also through the global withdrawal of it. It’s impossible to ignore the quiet (or not-so-quiet) shift from “we” to “me” over the past several years (decades?), now contributing, to some extent, to a body count.

A dangerous myth: Self-interest and global good are opposites

Over the past several years (decades?), a tug-of-war battle has been taking place between individualism and collective responsibility, becoming one of the defining tensions in American identity.

It’s not too hard to understand why. When systems fail people, like through crushing health care costs, stagnant wages, lack of accountability, and governments captured by private interests, people stop trusting those systems. If no one is coming to save you, you learn to save yourself. Sprinkle in profit and power grabs amid the vulnerability of division and isolation, and… here we are.

This personal survival instinct became a governing philosophy, then policy. Fields like public health, which have been built on the basic assumption that society as a whole values a collective approach, have been intentionally targeted. This thinking became so dominant, in fact, that people cheered when a chainsaw was taken to USAID—an organization that built clinics, trained health workers, funded labs, and supported rapid response teams in the places where outbreaks begin. Ebola is one of the first outbreaks unfolding in the aftermath of cutting this global health funding.

The prevailing idea is that what happens on the other side of the world has nothing to do with us. But this idea is a myth, especially when it comes to diseases, for three main reasons:

1. Americans are impacted by this Ebola outbreak directly, as they are being flown to another country to seek care.

2. We live in an interconnected world bound together by supply chains, air travel corridors, and accelerating disease spillovers from animals to humans. No wall can stop a pathogen, and neither can a travel ban.

3. The stakes are also economic. For example, when the U.S. invests in global health research and development, it can yield a sixfold return, including new jobs and economic activity. The Covid-19 pandemic cost 500 times what it would have to invest in proposed preventive measures to reduce disease spillover. The price of prevention is remarkably low, at less than 1% of the federal budget.

This week, the State Department seemed to realize the mistake and announced it will fund up to 50 Ebola treatment clinics in the DRC and Uganda, touting it as an “ironclad” commitment. Sure, treatment centers matter a lot if this actually happens. (As you can see below, the countries don’t even know this is happening.) But what works even better, and is more cost-effective? Helping prevent this in the first place.

True self-interest, rightly understood, is investment in global health. It is a myth that they are at odds.

The ethic of “just because”

But reducing all of this to strategy, or ROI, or soft power is, itself, a shortcoming. Strategy isn’t necessarily why people like the doctors and nurses of Médecins Sans Frontières have spent decades running toward the fire. They put their lives on the line because they simply care.

There used to be a shared value of foreign aid and international cooperation, broadly based on the idea that help was needed. The ROI was compassionate care for others as neighbors, grounded in empathy and equity. The ROI was saving lives and serving. That is enough.

The World Health Organization was built on this. The entire postwar international order, as flawed and incomplete as it often was, rested on the idea that nations had obligations to one another that went beyond what they could extract. That a human life had value that did not depend on its proximity to power, or its usefulness to anyone’s GDP. The value of a life, of all lives, matters and should not depend on where you live.

The Marshall Plan, for example, was not philanthropy because it was strategic. It was simultaneously multiplicative, collective, and synergistic. The people who built it did not find that troubling.

We have lost the animating belief that strangers’ suffering is our concern. That the provision of care is not decided by power but by compassion and collective empathy.

The cost is always paid by the same people

The most heartbreaking thing about all of this is that radical individualism doesn’t distribute its consequences equally. It always funnels suffering downward to the poor, the rural, and the people whose names don’t appear in the articles until they are counted among the dead.

Ebola’s geography is not an accident. Sure, it’s where the fruit bats live, but the cost is high for a reason. The cost lives where the hospitals don’t, where the roads end in mud, and the power cuts out, where the cold chain for vaccines has never been reliable, where the nearest trained physician might be two days’ travel away. It thrives in the gaps left by decades of systematic disinvestment, war, poverty, and a warming climate, and structural adjustment programs that stripped health budgets to the bone. Sometimes international attention arrives, but like many things in public health, it comes in cycles of panic and neglect. Once the cameras leave, so does the money.

The pushback seems to center around power and money. The same countries that hold most of the world’s wealth continue to be the most advanced in terms of health care workers, the number of medical facilities, and their ability to care for infectious diseases like Ebola. There remains a misconception that trickle-down economics and capitalism are the only ways for countries and people to thrive. In an ironic twist, investing and caring for the poorest of the poor first actually benefits all of us more. No matter how you slice the data, collectivism beats out individualism every time.

Research from one of us (Emily Smith) shows that when we start with the poor first, in a trickle-up economy, we actually fare better globally. Within and between countries, starting with the most vulnerable, is advantageous to all of us, fiscally, more than trickle-down capitalistic, individualistic approaches. This is health and wealth. But it only happens when we center the poor first. When the poorest of us are taken care of, we all thrive.

Bottom line

Ebola is called the disease of compassion because it spreads through caring for one another. What we are watching now is what happens when that caring is systematically dismantled. I hope the pendulum finds its way back to a place where compassion and the communal good can, once again, simply exist.

Love, YLE and FNE (ES)

Dr. Emily Smith (ES) is a global health epidemiologist, professor, and scientific communicator. She is the author of the Substack Friendly Neighborhood Epidemiologist (FNE) and the book Science of the Good Samaritan.

Your Local Epidemiologist (YLE) is founded by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE comprises a team of experts, ranging from physicians to immunologists to epidemiologists to nutritionists, working together with one goal: to “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. YLE reaches over 425,000 people across more than 132 countries. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

There was also a massive fly problem. It was so severe that the Greeks made ritual sacrifices to a deity they called Zeus Apomyios (which meant Zeus Averter of Flies). Before the Games, they appealed to a god specifically designated to keep the insects away.

The conditions were so notorious that ancient philosophers used them as a shorthand for human endurance. Epictetus asked his students: Are you not scorched? Are you not pressed by a crowd? Are you not without comfortable means of bathing? … Have you not abundance of noise, clamour, and other disagreeable things? But I suppose that setting all these things off against the magnificence of the spectacle, you bear and endure.

The World Cup kicks off in less than a month. It will be a magnificent spectacle and, thankfully, we don’t have to sacrifice to Zeus, as public health has advanced enormously in the past century. But the underlying challenge hasn’t gone away.

Here’s what’s happening in preparation and how you can get involved.

The world’s largest event

More than 100 matches will be played across 16 cities in the U.S., Canada, and Mexico over 38 days. Travelers from more than 48 countries will be flying in to watch and celebrate, with an expected 1.5 million additional inbound trips to the country. People will fill stadiums, spill into surrounding neighborhoods, pack bars and parks, and use public transit.

While this is a beautiful moment of celebration and the mixture of cultures, it brings enormous complexities to protecting the public’s health in two primary ways:

1. The sheer number of humans. High density = amplification of disease spread. Also, an influx provides added stress to health systems, like more broken bones, more heat-related illnesses, more (possibly violent) injuries, etc. For example, below are medical encounters before and during the 2022 World Cup in Qatar; they surged.

2. When people mix, diseases mix. New diseases could be introduced that we are not normally exposed to or immune to. A traveler from one region may carry a pathogen that’s routine back home but entirely novel to someone sitting next to them in the stands.

What are the diseases top of mind?

Some disease modelers are hard at work examining more than 80 diseases, and only a few show excess risk. At the top of the watchlist this summer:

1. Measles. This is surging in many parts of the world, and all it takes is one person to find a tightly knit, unvaccinated pocket to start measles spreading like wildfire.

2. Dengue. The U.S. has mosquito populations capable of carrying the virus. We haven’t seen widespread domestic spread, but the combination of summer heat, outdoor crowds, and high travel volume creates conditions worth watching carefully, particularly in southern states like Florida, California, and Texas.

3. High-consequence diseases. Many systems are gearing up to detect Ebola, hantavirus, and other rare pathogens. But the public risk remains low, including for Ebola, simply because of how the virus spreads (through direct contact with bodily fluids). It's worth remembering that the 2014 World Cup in Brazil coincided with the largest Ebola outbreak in history, and there was no outbreak there.

Beyond infectious diseases, heat-related illness may be the least dramatic item on the list, but it’s probably the most reliable risk. Crowds plus sun plus summer temperatures plus physical exertion plus alcohol is a combination that sends people to emergency rooms every year.

So what’s the plan?

Local and state health departments have been preparing. Many have activated their Emergency Operations Centers, which are the same command structures they use for natural events like hurricanes. Data systems are being tuned and tested to catch unusual signals early, before a cluster becomes an outbreak. Hospital systems are coordinating on surge capacity. Rapid response teams are on standby. Weekly coordination calls have already started in many jurisdictions.

This local preparation is essential as they know their communities best. But given movement across state and international borders, a national bird’s-eye view is also necessary to stitch together a broad picture of health around the World Cup.

One national effort in which YLE is playing a central role is the Health Security Operations Center. This will be held in person in Washington, DC, led by Dr. Rebecca Katz at Georgetown University. In normal times, this would reside within the federal government. This is the first-ever non-governmental operations center that brings together academic researchers, technology companies (like Verily and Samsung), and public health departments under one roof.

This will act as an intelligence fusion center pulling in data from wastewater monitoring, hospitals, contextual sources, and social listening. All of these data systems are built as underlying infrastructure, so they can turn on a dime for many diseases. (For example, wastewater monitoring for hantavirus is already turned on.) The goal is rapid detection of emerging health threats, with warnings shared across jurisdictions as early as possible, so people can take the necessary action.

YLE is charged with ensuring that the right information is delivered to the right people at the right time, so they can make the right decisions. This means leading information collection, social and media monitoring, “translation,” and dissemination.

What this means for you

During the games, be aware of your surroundings, consider using DEET, drink plenty of water, and wear a seatbelt. A mask can help in very crowded indoor settings. I will be sure to bring you along for the ride with what we are seeing in the data and what it may mean for you.

If you’re attending a game or live within 30 miles of a host city, we want to hear from you!

• What you’d be doing: Taking a short weekly survey. It’s a few questions about what health topics are on your mind, what rumors or concerns you’re hearing, and what questions aren’t getting answered.

• Why it matters: We will use your responses to directly address the questions and concerns most relevant to you in the Your Local Epidemiologist newsletter. We’ll also summarize the responses for our partners so that local health systems and governments can better address fan and community needs in real time.

• Sign up here, and we’ll follow up with everything you need to get started.

Bottom line

This summer, we will continue a tradition that has lasted for decades. Public health partners, and we will be watching the data carefully in the background so that millions of fans can be scorched, crowded, and thoroughly, joyfully present.

Love, YLE

Your Local Epidemiologist (YLE) is founded by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE comprises a team of experts, ranging from physicians to immunologists to epidemiologists to nutritionists, working together with one goal: to “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. YLE reaches over 425,000 people across more than 132 countries. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

That’s on top of tick season peaking and heat-related illnesses entering the picture. I end with some good news and a poll.

Here’s what’s going on and what it means for you and your health.

In case you missed it: NYT op ed

Last week, I wrote for the Times and, to my surprise, didn’t combust from nervousness.

It’s time to stop playing games and speak truth to power. The public deserves stronger, better systems. That’s not created by performative headlines or destruction alone; it also means not going back to 2019.

Here’s a gift link.

Disease weather report

Hantavirus update

The outbreak remains contained, and 41 people are being actively monitored in the U.S. Risk remains low for reasons previously covered.

A few updates:

1. People shuffling. The three people in biocontainment units (hospital-level setting) were moved to the Nebraska quarantine center (more like an isolated dorm room). All three tested negative, even the doctor who had a “mild positive.” It’s a telling sign of just how hard it is for this virus to spread; the doctor was treating infected patients on the cruise ship with very little PPE.

2. Are those in Nebraska able to go home? The federal government is forcing them to stay until the end of the month, even though some want to quarantine at home. This is pretty darn hypocritical given the administration’s medical freedom movement.

Countdown to mid-June. We’re in a waiting game to see if the outbreak grows. The 42-day quarantine clock starts from last exposure and CDC is assuming that was the day passengers arrived in Nebraska. The median infection window is 18 days, which is an intermediate target for good news.

What this means for you: Unless you’re a passenger or were alerted by health officials of a contact, your risk is essentially zero.

Ticks still ticking, but did they peak?

We are in peak tick season, especially in the Midwest and Northeast, where ~110 per 100,000 people visit emergency departments for tick bites.

But we may have already peaked, which is 5 weeks earlier than previous years. Whether this season is just early or will stretch on unusually long, time will tell.

Heat: Introducing a new section

Heat risk peaks today across Texas and the Northeast, then eases later in the week.

Heat sends more people to the ER with heat stroke, asthma attacks, dehydration, and heart problems. While relatively rare, it can also lead to death, which has increased over the past decade with more extreme heat. An increase in deaths outside largely drives this pattern. Indoor deaths are mostly among those without a working AC.

The real danger is heat imbalance. That’s when your body produces more heat than it can release. Normally, sweat helps cool us down. But when it’s hot and humid, sweat doesn’t evaporate as easily. The air is already saturated with moisture, making it harder for your body to cool itself and increasing the risk of illness.

Some federal tools were dismantled in 2025, but the NOAA-CDC HeatRisk tool remains active. This tool:

• Offers hyperlocal risk forecasts up to 7 days ahead.

• Rates conditions from “No Risk” to “Extreme” by considering temperatures, humidity, and other factors.

• Provides an action: what you and your family can do to be protected.

What this means for you: Over the summer, be sure to check the HeatRisk tool.* A red day isn’t the best day for that soccer game for a kid with asthma, and a stretch of orange days is a great time to check on your elderly neighbor.

*Disclosure: I helped build this tool as a Senior Advisor to CDC.

Spotlight: Ebola outbreak

A concerning Ebola outbreak is unfolding in Central Africa. This remains a very low risk to those in the U.S., but the WHO just declared it a public health emergency of international concern. Over 340 suspected cases and 100 deaths have been reported, and now there is a travel ban from three countries.

I called my friend Dr. Craig Spencer, a physician and Ebola survivor who worked in this region, to fill you in. Craig, take it away…

What is Ebola? It’s a virus you don’t want to mess with. It was first discovered in 1976 near the Ebola river (hence the name). It’s severe (25-90% case fatality rate). Symptoms include fever, severe headache, vomiting, and in serious cases, internal and external bleeding.

How did this start? We don’t know yet, but typically when a human comes in contact with an infected animal, usually fruit bats. From there, the virus spreads person-to-person. The people who take care of patients when they’re very sick—especially close family members and health care workers—are the most at risk. It spreads through direct contact with bodily fluids.

Why is this concerning? Four reasons:

1. This is not your normal Ebola. Ebola has six known strains. (The technical term is “species.”) Most outbreaks have been of the Zaire strain, and that’s the one we have vaccines and treatments for. But this outbreak is due to the Bundibugyo strain. This has caused a few small outbreaks in the past, but unlike the Zaire strain, there is no vaccine or treatment for this strain.

2. This outbreak is already big. Health officials learned about this outbreak long after it had already been spreading. This makes it really hard to find contacts and all the cases. Most outbreaks don’t get this big by the time they’re over, let alone this big by the time we even recognize them.

3. The location is exceptionally difficult. The outbreak is centered in eastern DR Congo, an area with significant conflict, cross-border traffic, and instability. There are also cases in the big cities here, which means a greater, faster spread due to the urban environment. I’ve worked up here; it’s a tough spot to get to and work in, due to transport and conflict. There was an Ebola outbreak here in 2018-2019 that grew to over 3,000 cases.

4. It’s on a few borders. This outbreak is close to the borders of Uganda and South Sudan. Uganda has extensive experience with Ebola outbreaks; South Sudan has less. We already know of two cases across the border in Kampala, the largest city in Uganda. And it’s possible there have already been cross-border cases into South Sudan and Rwanda, given the size of the outbreak. WHO and countries will be stepping up surveillance, but again, this is a place with a lot of conflict and instability.

This suggests the “true” outbreak is much larger, and that it will be tough to contain.

What triggers the declaration of a public health emergency of international concern (PHEIC)? WHO makes the PHEIC declaration based on three criteria:

1. It is unusual and unexpected.

2. There is the potential for cross-border spread.

3. It requires a coordinated, international response.

This is the ninth time it’s happened in history. But what is unique is that this is typically determined by committee. The director general declared PHEIC without convening the committee, hinting at the outbreak’s urgency. The outbreak was first announced on Friday, and a public health emergency was declared the next day.

This designation helps with emergency funding and signals to the world the urgency of the outbreak.

This has been spreading for awhile, without detection. Is this because of the cuts to USAID and global health efforts? They almost certainly played a role. U.S. funding once built strong surveillance systems around the world; without it, many of those programs are now shuttered. For example,

• USAID helped train communities on safer burial practices during the last Ebola outbreak and set up airport screening to prevent symptomatic travelers from boarding planes.

• CDC worked alongside affected countries and WHO to expand testing and coordinate the early response.

But the biggest loss was trust. Outbreak detection depends as much on relationships as technology. When we pulled our funding and support, we didn’t just lose the programs. We lost the credibility and the contact that made early warning possible. That’s almost impossible to rebuild quickly once an outbreak has already begun.

Does the travel ban work? Travel bans may seem like a necessary step, but they do not work unless you stop all travel from every country worldwide. Travel bans are often a political move; a tool to show the public that the government is responding. Travel bans can do a lot of damage in the meantime, like perpetuating disease-related stigma, reducing access to medical supplies, and more.

What this means for you: If you had travel plans to this region, it’s time to cancel them. This is a high-risk situation in Central Africa and CDC released a Level 4 Travel Advisory (i.e., the highest warning level.)

One American, a physician who was working in DRC on a mission, has tested positive. His family also had high-risk exposure. We have specialized treatment centers in the U.S. with experience taking care of Ebola patients, but the U.S. is sending them to Germany, arguing that its a shorter flight for the patient and their family.

To the general public in the U.S., your risk remains very, very low right now.

Good news

• Opioid deaths in the U.S. have declined for the third year in a row, driven by education and medical advancements. Harm reduction workers are noticing a less publicized reason: smoking is becoming more common than injecting. This shift may be saving lives because it allows people to better titrate their dose in real time, reducing the risk of a fatal overdose.

• Mifepristone was overruled by the Supreme Court. The Supreme Court blocked a Fifth Circuit ruling that would have required women to obtain Mifepristone through in-person visits, allowing telehealth and mail access to continue nationwide. This matters enormously for access: medication abortions now account for more than 60% of abortions in the U.S.

Bottom line

Public health is never boring—it can be slightly terrifying (and really sad) at times. Let this all be a reminder of why we need these systems in place, from local to state, federal, and global.

Love, YLE

Your Local Epidemiologist (YLE) is founded by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE comprises a team of experts, ranging from physicians to immunologists to epidemiologists to nutritionists, working together with one goal: to “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. YLE reaches over 425,000 people across more than 132 countries. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

First, I thought this would be an interesting, unique outbreak to “translate” to the public. But over time, public curiosity metastasized into a massive ball of anxiety in the headlines, online, and in some person-to-person conversations.

Right now, the outbreak remains contained, and 41 people are being actively monitored in the U.S. Risk remains low for a number of reasons previously covered. We will continue to follow it.

But when we pause from the numbers, transmission questions, and quarantine, and look up, the response to this outbreak is revealing a lot. Yes, how scary this virus is (it belongs in a thriller novel), and yes, the limits of our scientific knowledge. But also something far deeper.

What we are seeing is the collision of five factors that highlight not only how far we’ve come, but also how deep this country’s wounds still run, and how much work lies ahead.

1. Absent leadership.

Leadership at the federal level is nowhere to be found. Communication has been abysmal, much like it was at the beginning of the Covid-19 pandemic. After a week of silence, an alert was finally sent to physicians and a press conference was held.

But checking these boxes isn’t enough and has led to far too much deflection. For example, there are no numbers on the website, so no one actually knows who is being monitored, where, and how. This leaves massive information voids for falsehoods and rumors to fill.

But also, people don’t just need data or facts; they need steady navigators, grounded in empathy and knowledge, to wade through the oversaturated information landscape.

In crisis communication, a well-known formula is: outrage x hazard. So even if the hazard is low, if concern is great, you’d better be speaking with clarity, acknowledging uncertainty, listening to the questions, concerns, and confusion, and bringing people along for the ride.

What could this look like? Look no further than the WHO. The WHO director-general traveled to Tenerife in person to speak with residents who were terrified that a boat carrying a highly contagious disease was docking. He led with emotion, grounded in the understanding that 2020 was resurfacing for people, and focused on compassion and solidarity, elevating what one of the passengers said: “We’re not headlines, we are human beings.” In the meantime, they’ve hosted almost numerous live briefings on top of their daily updates on social media accounts and humanized the process with pictures. They aren’t just telling; they are showing.

2. The positive and negative aspects of Covid-19.

The hantavirus response is evidence that the learnings of Covid-19 stuck.

The pandemic became an involuntary crash course in epidemiology for the entire country. Epi 101, taught in real time to everyone at once:

• What transmission means.

• What incubation periods and case fatality rates actually tell us.

• The difference between droplet and airborne spread.

• What an R0 is.

• What it means when scientists say they’re still learning.

• And what, as individuals, we can actually do to feel in control.

During this time, public health was no longer invisible, which is beautiful because, after all, public health belongs to the public.

People now bring a depth of curiosity and literacy that simply wasn’t widespread even in 2018. If Covid-19 was Epi 101, this is Epi 201: taking what we learned from one pandemic and applying it to an entirely different disease.

The challenge with this is that we are changing lanes and, as Adam Grant said, “You don’t have to stay in your lane. You do need to check your blind spots before changing lanes.” After you’ve learned about one outbreak, you’ve learned about one outbreak. There are lessons the public can take, but it’s also easy to fall into blind spots of overconfidence. This is called the Dunning-Kruger effect.

3. The trauma of Covid-19 has not healed. Not even close.

It’s been six years since 2020, and life has returned to a version of normal. I think many had hoped, prayed, and assumed that the wounds of the Covid-19 pandemic had healed.

But when trauma is swept under the rug, it will eventually show its teeth.

A new outbreak entered the news cycle with a lot of the same themes: cruise ships, quarantine, WHO speaking up, scientists speaking up, headlines, uncertainty, and hard reminders of people saying “it’s fine, don’t panic.” So, internal threat systems went into overdrive. This is what our bodies are designed to do: respond to a new threat based on prior experience. It’s literally our survival mechanism.

As my friend Dr. Celine Gounder said: “The intensity of the reaction [also] tells you everything about the depth of the wound.”

4. Mistrust is pervasive.

This outbreak is showing that few people trust authorities and few trust their fellow Americans to do the right thing, like quarantine responsibly.

We entered the pandemic with a slow erosion of trust in institutions, such as government and the mass media. And it was deserved. Many institutions were built for a different time, and when institutions fail to adapt, people are left behind, and trust erodes.

The pandemic accelerated mistrust on one side. For them, the experience felt like an overreach. A government that moved to control behavior, restrict movement, and mandate compliance, often without consistent logic or transparency.

But then, after the pandemic, the pendulum swung violently in the other direction. What felt like a restoration of sanity to some felt like an abandonment of truth and decency to others.

The tribalism has become so strong that it’s not only eroded trust in the systems that are supposed to keep us safe, but also in each other.

This is not only deeply heartbreaking for society, but also leaves us incredibly vulnerable to threats within and outside of our country.

5. Social media and the hurting media economy are fueling the embers.

An accelerant is the information landscape. Information is spreading like wildfire on social media, adding extraordinary complexity for people earning to understand what to believe, from whom, and when.

Social media algorithms and news headlines are built to play on emotion and engineered to surface rage and fear because rage and fear make us scroll, click and sells ads. This creates a seriously challenging echo chamber all of us can get stuck in, where we think every conversation is like the one we are in.

At YLE, we saw this in real time. Not only do we do social listening on the backend, but we also have a weekly survey to understand things not in the media environment. Usually what we hear from these sources matches; after all, 1 in 2 Americans get their health-related information online. But this week was different: on social media, there was spiraling. In the survey? Only 20% were concerned; 60% were just curious about what was going on.

So where does this lead us?

If you felt something or saw this beneath the surface these past two weeks, you’re not alone. What we are experiencing is a deep collision of massive forces, with all of us stuck in the middle.

As a society, we have serious work to do. We need to reckon honestly with the trauma we never processed. And our leaders and institutions need to stop talking about rebuilding trust and actually do it.

For individuals, I think this means:

• Keep learning Epi 201. Lead with curiosity and humility, as many people are taking the course.

• Triple-check your sources and be sure to share trusted information. Here are nine ways to spot falsehoods that I wrote about a few years ago.

• Give yourself grace—and give it to those trying to communicate in real time, in an arena where the answers aren’t always clear yet.

• Put down social media. Have conversations with people outside your bubble. Get involved in your community. This country is deeply wounded, and change and sanity start locally.

Bottom line

Hantavirus may be contained. But the conditions that made these two weeks so destabilizing are not. The real outbreak is one of fractured trust, unhealed trauma, and absent leadership. No one is coming to fix it but us. We all have a role to play.

Love, YLE

Your Local Epidemiologist (YLE) is founded by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE comprises a team of experts, ranging from physicians to immunologists to epidemiologists to nutritionists, working together with one goal: to “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. YLE reaches over 425,000 people across more than 132 countries. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

There’s also all the normal stuff going around: Peak tick and allergy season, norovirus surges on another cruise ship, and scientific wins worth celebrating.

Here’s The Dose: what’s going on in the world of health and what it means for you.

Spotlight: 4 updates on the hantavirus outbreak

The risk to the general public remains exceptionally low, but the situation continues to march forward for the high-risk cruise passengers.

Note: If you missed it, this post builds on last Friday’s. You can catch up here. And big thanks to the entire YLE team, from virologists to physicians to epidemiologists, helping keep track of this rapidly moving situation.

1. Touchdown in Nebraska

Yesterday, 18 Americans landed safely in Nebraska by private transport after disembarking from the cruise ship in Spain.

Why Nebraska? In 2019, your federal tax dollars paid to build the only national quarantine facility in the U.S. specifically designed to safely monitor individuals exposed to high-consequence disease. This facility has a college-dorm feel, complete with TVs and exercise machines (see picture below), but people are completely separated. They don’t share air and don’t mingle. This facility was built for situations just like this.

Down the street, there is also a biocontainment unit, similar to a hospital room but with many more precautions to safely treat someone who becomes ill. Importantly, Nebraska isn’t the only biocontainment unit. The U.S. has a network to help distribute people in situations like this. All of these systems are activated.

So, out of the 18 people:

• Fifteen are in the Nebraska quarantine center: They are resting, being screened, and participating in detailed interviews to establish underlying health, exposure timelines (quarantine clocks start at the last exposure, so the interview matters), and their home situations to determine whether they can safely quarantine at home (distance from a hospital, home situations, etc.). None have symptoms.

• One person is in the Nebraska biocontainment unit. They tested positive for hantavirus without symptoms. Hantavirus can turn positive on PCR testing before symptoms arise and before it becomes contagious.

• Two passengers went to the Atlanta biocontainment unit. This is a couple: one person has mild symptoms, and the other has no symptoms. Importantly, symptoms of a cold or stomach bug at this stage may warrant a visit to this unit. (Remember, there was a flight attendant who was presumed to have hanta, based on her symptoms, and she ended up testing negative and recovered.)

In addition, there are seven Americans in quarantine at home across five states who were on the ship after the initial case died, but before public health authorities knew this was an outbreak. There are also ~11 people exposed to these cruise passengers while flying. None have symptoms, and all are in close contact with local public health departments.

2. The debate on whether to send passengers home intensified

After the home assessment, if they remain symptom-free, CDC will give those in the Nebraska quarantine facility a choice: stay or return home on a charter flight (not commercial) and stay in close, daily contact with local health departments. Either way, a full 42-day quarantine is expected.

A lot of people disagree with this move. After all, requiring people to stay in Nebraska reduces the risk to everyone else to zero. And, we are living in a very low-trust environment. Offering this option is asking communities to trust that those people will remain in quarantine and cooperate.

But, as with any public health decision, there are real trade-offs to consider. This is both a public health and humanitarian response:

• Public health goal: Reduce risk to the passenger and the community. To do this, the most important thing is not necessarily where they are, but that they are monitored daily, remain quarantined (meaning they do not mix with other people), and have access to an appropriate hospital if they get sick.

• Humanitarian goal: Allow passengers to quarantine where they prefer, such as at home. They were in international waters and living in a nightmare for more than a month. There’s a real psychological toll to that.

It doesn’t seem any individual has made a decision yet. And there is a possibility that pressure is enough to prompt the administration to change course. But I think the best option is the least restrictive approach that still keeps communities safe.

3. Transmission: How close is a close contact?

I know people are worried about this one, so let’s talk about what we do and don’t know.

We do know that there are two primary ways Andes hantavirus spreads: through contact with infected rodents and through “close contact” with people who are both infected and symptomatic.

We also know that the first passengers to be infected with the Andes virus were exposed in the most typical way: through contact with infected rodents off the boat. The next two cases also contracted the virus in a typical way: through close contact with infected people. (Close contact is defined by CDC as 6 feet for more than 15 minutes.) Cruise ships are notorious for putting people into close contact.

But, during a 2018 Argentina outbreak, a symptomatic patient infected 5 people while sitting close at a birthday party. One case may have involved only a brief, passing interaction. That said, 94 other partygoers didn’t contract the virus, and 82 healthcare workers who cared for the resulting patients remained healthy, many without PPE. (See a deeper dive from Ed Nirenberg here.)

Getting the transmission pathways matters a lot for contact tracing to ensure everyone who needs to be monitored is monitored (like on a flight). It also matters that scientists collect the right specimens on the ship so we can learn more.

In general, though, the overall risk of a pandemic remains very, very small, especially when added to a few other things we know:

1. We’ve successfully stopped Andes outbreaks in the past through standard contact and droplet precautions.

2. This does not appear to be a highly contagious virus between people.

3. Variants don't appear to be a concern here. Scientists confirmed this week that passenger samples were almost identical to one another and to samples from 1997 and 2018. This virus is behaving as scientists expect.

I will start worrying if we start seeing new infections among people who were not on this ship and had no contact with a positive case. (We haven’t seen this yet.)

4. HHS communications finally woke up

Over the weekend, physicians received a HAN (a routine alert about what to watch for), and the CDC website was finally updated, followed by a press briefing yesterday morning. Better late than never, but the drip of information has made all of this genuinely difficult to track. WHO remains stellar in communications.

What this means for you

The risk to you remains extremely low, and, thankfully, we have systems in place to address this rare disease. There is no need to cancel trips and this is not another Covid-19. The most important thing you can do is help spread accurate information. Triple-check sources, don’t spread unverified rumors, but DO share reputable and verified information. This includes information from the WHO, local health departments, and reputable public health leaders.

Disease weather report

While this small but deadly hantavirus outbreak plays out, there are four other pathogens that are more likely to affect your health right now.

Ticks: Are they slowing down?

Tick bites are certainly earlier this year than in previous years, but it’s not clear whether this will translate to a more severe season. After some exponential growth, the rate has come to a slow crawl. Regardless, we are in peak tick season.

What this means for you: Prevention goes a long way. Most pathogens can only be transmitted after a tick feeds for some time, so call your physician if one has been attached for 36 hours. Use tweezers for removal (the only recommended method). And remember: nymphs are the size of a poppy seed.

Feeling crummy? It’s likely the common cold and/or allergies

Common colds are approaching their spring peak while other respiratory viruses become dormant. If you’re feeling crummy right now, it’s probably a cold.

Or it may not be a virus at all. This week is going to be another bad one for people with allergies, particularly in the North and Midwest.

Allergy season is getting longer and more intense. Plants are releasing pollen about 40 days earlier than they used to and stopping about two weeks later, thanks to rising temperatures. Higher CO2 levels mean more pollen per plant.

What this means for you: Check the pollen forecast, rinse your nose with saline (use distilled water), and shower before bed to wash pollen off. For medication, go with second-generation antihistamines like Zyrtec over Benadryl. (Benadryl has been around since the 1940s but carries more side effects.) Always check with your doctor. Also, here is a great room-by-room guide you may find useful.

Another cruise, another outbreak: Norovirus

Another cruise ship made headlines last week due to a major norovirus outbreak with more than 115 cases. Norovirus—think nausea, vomiting, and diarrhea—is also midseason but on its way down.

Norovirus is very infectious. On average, one infected person will infect two to seven other people, and the virus can live on surfaces for weeks.

And while cruise ship outbreaks usually make the news (like this one), they only account for 1% of outbreaks. Three out of four norovirus outbreaks occur in nursing homes. Restaurants and schools are the next most common settings.

What this means for you: Norovirus is extremely contagious. If you have the stomach bug (assuming you’re not reading from the cruise ship), use a separate bathroom in your house. Hand sanitizer doesn’t kill this bugger, either. Soap and water are your best bet after touching hotel door knobs or elevator buttons, for example. If you’re second guessing your cruise plans, read on for our take.

Good news

• Wastewater is here to help with measles. A new study found that wastewater monitoring enabled officials to detect a measles outbreak in New Mexico five days earlier than clinical testing. Given this is such a contagious virus, this could really help get on top of outbreaks before they get out of control.

• Suppressing HIV could become more successful and more manageable. HIV requires lifelong treatment, which currently means daily medication for most patients. Scientists found that one infusion of immune cells that recognize HIV reduced the virus to undetectable levels. Only a couple of patients have received this treatment so far, but its success—for one patient, HIV remained undetectable for two years after that one infusion —is a milestone for treatment options.

Question grab bag

These outbreaks have me reconsidering my cruise plans. Are cruise ships really floating petri dishes compared to other settings?

Cruise ships have a reputation as floating petri dishes.

Some of this is a monitoring artifact. The CDC's Vessel Sanitation Program requires cruise ships to report outbreaks and maintains a public database of all reported cases, which doesn’t exist for hotels, resorts, college dormitories, or restaurants, where the same viruses spread just as readily but without mandatory public reporting. So public health is looking for outbreaks, like norovirus.

That said, the environment does matter. Dr. Adam Kucharski shared his interesting research on social mixing, which found that cruise passengers have nearly twice as many close contacts per day as people on land (20 versus 10). This means more opportunity to catch something.

In 2020, the Diamond Princess became one of the most studied natural experiments in infectious disease history. One study found that Covid-19 airborne transmission likely accounted for more than half of disease spread on the ship, a finding that reshaped thinking about ventilation in enclosed spaces well beyond cruising.

If you do cruise, the single best thing you can do is wash your hands before and after every meal, every time. And stay behind if you’re sick.

Bottom line

Public health is never dull, but beneath the alarming headlines, there are systems, scientists, and dedicated people quietly doing their jobs to keep you safe and largely succeeding.

Love, YLE

Your Local Epidemiologist (YLE) is founded by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE comprises a team of experts, ranging from physicians to immunologists to epidemiologists to nutritionists, working together with one goal: to “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. YLE reaches over 425,000 people across more than 132 countries. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

Here’s the latest.

Note: If you missed it, this post builds on the live briefing from Wednesday. You can find it here.

Situation report

1. Case count has remained stable. There are still three deaths and five cases. I hope it stays this way, but there is a chance (and I expect) it will increase over the next six weeks. This virus has a long incubation period, up to 45 days (median 18 days), during which it can enter the body, latch on, and wreak havoc. Unfortunately, we are at the mercy of time and biology.

2. Risk to the general public remains low, per the WHO. I agree with this assessment. Risk is probabilistic: what’s possible isn’t what’s probable. The odds of this escalating are low for several reasons:

   1. This isn’t a novel virus. We’ve known about Andes hantavirus since the 1990s. We have prior data about how it spreads, where it’s located, and how it acts. That’s different from Covid-19.

   2. Past Andes hantavirus outbreaks typically involve close-contact settings, such as caring for a sick person or sleeping in the same bed. To our knowledge, this isn’t spread asymptotically. Some research shows spread through more casual contact, but all prior outbreaks have been contained successfully. In this outbreak, all cases so far are linked to close contact. This helps with containment.

   3. Like many viruses, Andes can mutate randomly or reassert, but it doesn’t have a track record of rapid mutation, making it hard to change the circumstances quickly. WHO has confirmed that this holds here—the sample in South Africa is nearly identical to the version seen in Argentina.

3. Off the boat, there is extensive contact tracing. Thirty people got off the boat after the first death (and before officials knew this was an outbreak). They are now being contact-traced by epidemiologists. This means alerting those passengers, monitoring for any symptoms, tracing their steps (such as boarding a plane), and alerting those who are near them for an extended period. None of these passengers has symptoms so far. Six are Americans and live in California, Georgia, Virginia, and Arizona.
   
   Note: Because there is a lot of contact tracing, you may start hearing rumors about more positive cases, like a flight attendant. These may turn out to be truly positive, but importantly, having symptoms does not mean it’s hantavirus. Epidemiologists discern correlation from causation by understanding risk (like where contacts are relative to the patient) and by sending the test to confirm. This takes time.

4. On the boat, people will get relief soon. Three sick passengers were evacuated from the ship to a hospital yesterday, which is excellent news. Hospitals have specialized airborne isolation units designed exactly for situations like this. The ship is now heading toward islands near Spain, which have agreed to allow it to dock. It should reach there by Monday. It’s still unclear what the long-term plan is, but I hope passengers will be able to safely isolate closer to home and near their families.

5. The international response has been fantastic so far. I continue to be impressed by WHO’s coordination across multiple countries, their public briefings, the swiftness of contact tracing and testing, and their success in negotiating with Spain to allow the boat to dock.

6. This is an evolving situation, and we will learn more in the days ahead. It’s possible that some early information may be inaccurate, and we will learn new things about this virus that we didn’t know before. That uncertainty is uncomfortable, but it’s also a normal part of the scientific process.

7. There’s understandably a lot of fear around this outbreak. This is a really scary virus, like one you would expect to see in a movie. We are also on the heels of the pandemic, and there are some similar vibes (e.g., cruise ships, quarantining, WHO briefings, scientists speaking out). And we’re living in an incredibly low-trust environment, both with our government and amongst ourselves.

Is our government responding appropriately?

Public health scientists are on it. CDC scientists are actively involved behind the scenes, including standing up an Emergency Operations Center and coordinating with the WHO. (They are allowed to talk to WHO for this situation.) States are also activated and have initiated contact tracing and coordination. This is exactly what we train for, and these guys are working incredibly hard under difficult circumstances: significant funding cuts, a workforce that’s lost roughly a third of its people, research on Hantavirus halted, and institutions under enormous strain for the past 14 months.

That said, I do have some major questions for CDC leadership and the administration. I want to know:

1. Why haven’t they deployed a team to help with the international response?

2. Why haven’t physicians been alerted through the Health Alert Network (HAN) as they typically would?

3. Why is there zero communication with the public or updates to the website?

This is abnormal. The muffling of scientists and the lack of transparency are unacceptable for Americans’ safety and security.

What this means for you

To the general population, your risk is close to zero. I loved this graphic that my friend Dr. Caitlin Rivers put together in the New York Times.

Right now, people are focused on this outbreak and want to take action. This is an understandable response. The most important thing you can do is help spread accurate information. This means:

1. Triple-check sources, and don’t spread unverified rumors. There are a lot of rumors and speculation right now, but often they turn out not to be true. (The flight attendant is a great example; many assumed she had already tested positive, which wasn’t true.) Not sharing or spreading something until it’s verified helps prevent the spread of inaccurate information and keeps our stress levels down.

2. DO share reputable and verified information. This includes information from the WHO, local health departments, and reputable public health leaders.

This is also a reminder that a type of hantavirus does live in the U.S. It’s also very rare and does not spread person to person, but we can take action in rodent-infested areas, like barns.

Bottom line

This is a serious, unique international outbreak. Things are moving quickly, but this virus is behaving as we expect so far, and it’s a low-risk situation for the general public.

This is public health in action. Let it be a reminder of why we need these systems in place, from local to state to global health.

Love, YLE

Your Local Epidemiologist (YLE) is founded and operated by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE reaches over 425,000 people in over 132 countries with one goal: “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

The Hantavirus outbreak is a rapidly evolving situation, and rumors and falsehoods are spreading. Dr. Marisa Donnelly (author of YLE NY and former CDC EIS officer) and I broke down what we know so far, how we’re thinking about it, clarify that CDC (and their brilliant scientists) are involved, and bring you along on this scientific discovery ride. Here is the recording.

Bottom line

This is not Covid-19. But it is a serious, unique outbreak with no playbook. Things are moving quickly, but this virus is behaving as we expect. The WHO says this is still a low-risk situation for the general public, and I agree. Our hearts are with the people on the ship in this nightmare situation. Right now, there is no action for the public to take.

I will be back with more as this situation unfolds.

Love, YLE

Your Local Epidemiologist (YLE) is founded and operated by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE reaches over 425,000 people in over 132 countries with one goal: “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

Abortion had been illegal in Brazil since 1890, so women who needed one faced a brutal menu of options that were dangerous, expensive, and often deadly. In fact, unsafe abortions were one of the leading causes of maternal death in the country.

But then, in a five-year span, Brazil’s maternal mortality rates fell 21%. It turned out that Brazilians in need of an abortion read the “do not use if pregnant” warning on Cytotec bottles and quickly realized that it worked as an abortion option. Word moved through whisper networks from neighborhoods in Recife to pharmacies in São Paulo, and Brazilian pharmacists started to recommend the product for safely terminating pregnancies as a workaround around the criminalization of abortion.

Brazilian doctors started calling the Cytotec medication “Saint-otec” because far fewer women were dying from abortion complications thanks to this ulcer pill.

That was nearly forty years ago.

Today, American courts threaten access to abortions in the U.S. with the restriction of mifepristone, an abortion pill used in ~65% of U.S. abortions, which dominates every headline. The legal, medical, and public health implications are enormous.

But regardless of what happens in courts, American women have access to the same lesser-known option that changed everything in Brazil. Most don’t know it exists.

The other option: Misoprostol only

If you’ve been following the news about medication abortions, you’ve probably been picturing one pill. But for a medication abortion in the U.S., patients are given two: mifepristone (”mife”) followed by misoprostol (”miso”).

The legal cases have focused entirely on mife, because it was specifically approved by the FDA in 2000 for abortion. Miso’s FDA approval, by contrast, still officially says “stomach ulcers.” This is the same ulcer drug Brazilian women figured out forty years ago. It has simply been used off-label for abortion, labor induction, postpartum hemorrhage prevention, and more ever since.

Why isn’t miso only routinely used in the U.S.?

Clinical consensus holds that the combined regimen (mife+miso) is slightly more effective at ending a pregnancy than miso alone. This is primarily based on pooled data from a wide range of studies that included various ways people can use the medication, i.e., different dosages, routes of administration, and dose intervals.

But when scientists review studies on the currently endorsed miso-only regimen (3+ doses of 800 ug miso taken every 3 hours), miso-only may be more effective than commonly thought. A 2024 analysis looked across eight study groups that examined 3+ doses of miso only: ~90% had a complete abortion (compared to ~95% expected for the combined mife+miso regimen).

Miso only for abortion is also safe: only 0.7% of ~12,000 users from a 2019 meta-analysis had a blood transfusion or were hospitalized for abortion-related reasons.

Some people worry that using miso only may be a more physically uncomfortable way to terminate a pregnancy than mife+miso due to the gastrointestinal effects of miso, but the comparative research on this is weak. A Cochrane Review concluded no difference in side effects, except maybe more diarrhea with miso-only.

More research is needed, and some is already underway. Researchers are leading a randomized controlled trial in the U.S. to collect MUCH more detailed data on the side effects of the miso-only regimen compared with the mife+miso regimen, so that patients and providers alike know what to expect.

Restricting mife is still unconscionable

The medical evidence is overwhelmingly clear: use of these pills is medically safe—safer than other medications we routinely use, and certainly safer than childbirth. The National Academies of Sciences, Engineering and Medicine even released a comprehensive report emphasizing the safety of abortion care, including medication abortion.

These medications are also highly effective for ending pregnancies and result in a complete abortion in nearly all cases. In fact, in March 2022, the WHO strengthened its guidelines on medication abortion, taking into account evidence over the past decade on self-managed medication abortion as a safe and effective model of abortion care (not “just” as a last resort).

What this means for you

As this plays out in court in a loud, confusing, and exhausting way, one of the quietest forms of harm in reproductive health care is when people don’t know all their options, and the choice gets made for them.

Abortion is one of the more common health experiences we have, so having information for yourself or your loved ones is imperative.

1. Spread the word: medication abortion access has not ended. Regardless of what happens with mife in the courts, all of us deserve accurate information, compassionate care, and the ability to make decisions about our own bodies.

2. Trusted sources for finding care include INeedAnA.com or AbuzzHealth.

3. If you need legal advice, call If/When/How’s free Repro Helpline: 844-868-2812.

4. If you’re going through this alone, you don’t have to. Call the Miscarriage and Abortion Hotline. They’re here for you: 833-246-2632.

No matter what happens with this current case on mife, patients will continue to need abortion pills, and dedicated clinicians and advocates will still have a solid option to provide them.

Bottom line

Restricting access to mife is epidemiologically baseless given 26 years of robust safety and effectiveness data. Yet, even if Americans ultimately end up with constrained choice, not all medication abortion is off the table. People will still have access to a safe and effective method of medication abortion care: miso only.

Let’s hope it doesn’t come to this, but whisper networks still work, just ask Brazil. Pass it on.

Love, YLE and HM

Heidi Moseson, PhD, is a reproductive epidemiologist and scientist at Ibis Reproductive Health. She studies abortion access in the U.S. with a particular focus on self-managed abortion with medications.

Your Local Epidemiologist (YLE) is founded and operated by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE reaches over 425,000 people in over 132 countries with one goal: “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

Let’s dig in!

Disease weather report

Ticks keep on ticking

It’s an unusual year for ticks. Emergency department (ED) visits for tick bites are running at roughly 114 per 100,000 people per week, nearly double the typical rate at this time in previous years (60-70 per 100,000). The Northeast is bearing the brunt of it, with the Midwest running a close second.

It’s not clear whether this is just an earlier year or a worse year overall. Time will tell.

ED data are a remarkable window into public health because data are quick, and so many Americans use emergency departments as their primary or urgent care.

Why are people going to the ED for a tick bite? Four main reasons:

1. They don’t know what to do. It's hard to know whether a bite is dangerous, how long the tick has been attached, or what symptoms to watch for. When in doubt, people default to the place they know will help, and that’s the ED.

2. They can’t remove it safely on their own. Removing a tick incorrectly (such as burning it or smothering it with petroleum jelly) can cause it to release more saliva and, theoretically, increase the risk of infection. If someone can't see it well, can’t reach it, or is too anxious to do it calmly, getting a clinician’s hands and eyes involved is helpful.

3. They need antibiotics. If a tick has been attached long enough in a high-risk Lyme area, a prophylactic dose of doxycycline is genuinely time-sensitive, though urgent care or a family doctor can handle it just as well.

4. They have symptoms that are emergencies, such as anaphylaxis or tick paralysis.

What this means for you: Prevention goes a long way. Most pathogens can only be transmitted after a tick feeds for some time, so call your physician if one has been attached more than 36–48 hours. Use tweezers for removal (the only recommended method). And remember: nymphs are the size of a poppy seed.

Feeling crummy? It’s likely the common cold and/or allergies

The common cold is approaching its spring peak while other respiratory viruses become dormant. If you’re feeling crummy right now, it’s probably a cold.

Or it may not be a virus at all. Much of the U.S. is suffering from allergies, and allergy season is getting longer and more intense. Plants are releasing pollen about 40 days earlier than they used to and stopping about two weeks later, thanks to rising temperatures. Higher CO2 levels mean more pollen per plant.

What this means for you: Check the pollen forecast, rinse your nose with saline (use distilled water), and shower before bed to wash pollen off. For medication, go with second-generation antihistamines like Zyrtec over Benadryl (Benadryl has been around since the 1940s but carries more side effects.) Always check with your doctor. Also, here is a great room-by-room guide you may find useful.

Spotlight: What hantavirus and a cruise ship are reminding us

Over the weekend, news broke of a small but alarming outbreak aboard a cruise ship traveling from Argentina to South Africa: three deaths, one critically ill, and three additional suspected cases of hantavirus. (Two cases have been confirmed so far.)

Hantavirus kills 40–60% of those it infects, making it one of those viruses that would make a terrifying movie. While it is very rare, random cases do pop up—even in the U.S.—when rat droppings are aerosolized. (You may remember Gene Hackman’s wife, Betsy Arakawa, died last year in New Mexico.) But this situation is unusual because multiple cases are suspected within a very confined space, and the ship is coming from Argentina, which is home to a particularly nasty strain of hantavirus. (More below.)

So disease detectives are working urgently to piece together what happened to these seven people, assess the risk to everyone else on that ship, and the risk to South Africa (and the world) waiting at the other end. Five questions, specifically, are worked in parallel:

• Are there more cases? The ship hasn’t been allowed to dock, and passengers are being asked to monitor symptoms. Unfortunately, the incubation period (how long the virus lives before symptoms arise) can be weeks. I can’t even imagine how terrified these poor passengers are because of the level of uncertainty.

  • This situation is ethically extremely tricky: isolate the people on the ship that may contain an exposure source vs. deboard all 150 passengers and isolate them as best as possible. Deboarding comes with risks. The risk-benefit final decision is made by the cruise operator, the ship’s captain, the Cape Verde health authorities, the WHO, and the governments of the nationals on board.

• Where did it come from? Hantavirus lives in rodents. Did someone encounter infected droppings at a port stop in Argentina? Is there a rodent on the ship that is spreading droppings throughout air vents? Investigators are testing rodents and any droppings found onboard.

• What do patients have in common? Epidemiologists are mapping each case: cabin location, dining arrangements, shore excursions, and daily routines. They’re looking for the thread connecting these seven people and separating them from hundreds of others who are so far okay.

• How is it spreading? Hantavirus is not typically transmitted person-to-person. It is known to spread when people inhale aerosolized particles from infected rodent urine, droppings, or saliva. But, importantly, there is one type of hantavirus that can spread from person to person, and guess where it comes from? Argentina (where this boat sailed from). Investigators need to confirm how this outbreak is spreading because if person-to-person transmission is occurring, the risk calculus changes quickly.

• What is the pathogen itself? The virus is being genetically sequenced to determine its strain and whether it has mutated.

Answers to these questions will come, but there is a silver lining. This is unfolding in South African waters. South Africa has very fast data, is home to some of the world’s best epidemiologists, and is a true team player in the world of global health, willing to work with (and alert) other countries.

What this means for you: Risk to Americans is essentially nil right now, and the probability of a pandemic remains very, very low.

But let this be a reminder that diseases don’t see borders. As the U.S. pulls back from institutions like the World Health Organization, it weakens epidemiologists’ ability to communicate across countries, ultimately undermining our ability to protect Americans.

Question grab bag

My grandpa asked me this, so I suspect it’s on a lot of minds: Do I really need a spring Covid shot?

My answer to him: It’s messy, but I would say yes.

Current CDC guidance recommends two updated doses per year for people over 65: one in fall, one in spring. A recent CDC study (blocked from publication by political appointees, but valid) found that the winter vaccine continues to provide 55% additional protection against severe disease and death. Last year, around 40,000 people still died from Covid-19.

That said, robust data comparing one versus two annual doses are genuinely scarce. What we do know: summer Covid waves have occurred for six straight years, and recent summer waves have been larger than winter ones. If that pattern holds, June or July is when things pick up, making late May the sweet spot for vaccination.

Age matters, too. Older immune systems have a harder time holding onto immunological memory, which is why the guidance skews toward more frequent boosting for seniors.

The data aren’t perfect, but for older adults, the benefits still outweigh the risks.

Good news

• Infant formula is (confirmed) safe! A new FDA report tested infant formula for heavy metals (arsenic, lead, cadmium, and mercury) and PFAs. Levels were well below European standards, which are the strictest in the world.

• Physician burnout is declining for the third consecutive year, to 41% (down from 48%). Although there is a whole lot more progress to be made, it is important to understand what is driving this trend and keep pushing for structural changes.

• There was a big drop in bird flu detections last week. It’s the turn of the season, and detections are down among backyard chickens, commercial farms, and wild birds. Last week brought only one new report of a poultry facility with H5N1.

• A Danish study showed promising impacts of Wegovy, an obesity drug, on heavy drinking. In the 108-person study, people with alcohol use disorder and obesity reported reduced days of heavy drinking in a month-long period (–41·1 percentage points) than before they started on Wegovy. This is the first controlled trial that looked at impacts of the drug on alcohol consumption. It’s a small study, so there’s more work to be done, but the results are promising.

Bottom line

We may be out of the winter season, but public health never gets boring. Stay healthy out there!

Love, YLE

Your Local Epidemiologist (YLE) is founded and operated by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE reaches over 425,000 people in over 132 countries with one goal: “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

This month:

• What health issues do Americans actually worry about? In California, rattlesnakes and water rationing—not what health systems are talking about. Feedback loops are needed now more than ever so people feel seen and heard and, ultimately, empowered to lead healthy lives.

• Five scientific studies that caught our attention, including the positive impact of flu vaccines on dementia, early evidence that GLP-1s do not cause muscle loss, and the effectiveness of lower LDL levels.

• The dark side of the internet has a new trend: managing menopause symptoms online.

Let’s dive in!

Read more

But first: why should you care? Learning to identify logical fallacies is a form of prebunking. There are SO MANY false health claims on the internet, and chasing them down one by one is not possible. Instead, if you can learn to recognize these common errors in reasoning and manipulative patterns, you can be prepared to discern unreliable information when you encounter it in the wild.

And research has shown prebunking works: teaching people logical fallacies helps them discern what information is reliable, and what is not.

Alright, now to the fallacies.

Anecdotal fallacy

The anecdotal fallacy occurs when people use their limited personal experience to make sweeping conclusions. Our personal experiences are important, and they guide many of our decisions. But they also often give us incomplete information because they only reflect one experience or point of view. The error in reasoning occurs when a person assumes their limited experience provides complete information and is enough to make much broader conclusions.

Examples of this fallacy in action:

• My child didn’t get vaccinated and they’re fine! (anecdote) Vaccines aren’t really needed. (broader conclusion)

• I stopped eating bread and felt better (anecdote)—gluten is causing so much inflammation in the modern diet. (broader conclusion)

• I started taking this new supplement and have so much energy (anecdote)—it really works! (broader conclusion)

Appeal to emotion fallacy

The appeal to emotion fallacy tries to win an argument not by providing evidence, but by distracting people with strong, emotionally charged language or imagery to evoke feelings such as fear, anger, or sadness.

The image below is a great example. It was used to try to convince Americans that children in the U.S. receive too many vaccines. Instead of providing accurate data, the image triggers an emotional reaction by using images of lots of needles, which feels scary, and by showing the U.S. baby as unhappy (frowning).

This emotionally charged imagery distracts people from the fact that the message is inaccurate. U.S. babies do not receive 72 injections, and the image creates a distorted view of immunization by emphasizing fear of needles while ignoring the benefits.

Emotion, by itself, isn’t inherently wrong or invalid, and it can be used appropriately in health messaging. The error in reasoning occurs when emotion is used in place of a reasoned argument, or when it is used to distract from the fact that insufficient or inaccurate evidence has been provided (as was the case here).

Appeal to authority

The appeal to authority fallacy says that authority figures (experts) are always right. But this is not always true; reality does not bend to the will or whims of experts. Right now I think this one is especially confusing, because the scientific community says “trust the experts!” but then when an expert says something a bit weird, they say “ignore them!”

In science, what ultimately matters is the quality of the data and analysis—not who is making the claim. Experts are often more reliable because they’re trained to evaluate evidence, which is why it usually makes sense to trust them.

But their credentials alone aren’t proof—people with MDs and PhDs have to provide data to back up what they’re saying. The error in reasoning comes from assuming that a person’s title or credentials alone are enough to say they are correct, without requiring they provide additional evidence to support their argument.

Examples of this fallacy in action:

• “Dr. Malone is the inventor of mRNA vaccines; he knows what he’s talking about!”

• “I’ve seen five doctors online recommend this supplement—it must work.”

• “A Harvard study showed Tylenol during pregnancy is linked to autism, it must be true!”

Moving the goal posts fallacy

The moving the goalposts fallacy occurs when someone refuses to accept valid evidence supporting an argument and instead changes their demands. This tactic makes it so an argument is never settled because the demands are constantly changing.

One of the most famous examples of this fallacy is the rumor around vaccines and autism. Back in the 1990s, the original argument was the MMR vaccine may be linked to autism. This was studied extensively, and no link was found. But instead of saying “oh that’s great!” the goalposts changed and the rumor lived on: next it was alleged it was actually thimerosal (a vaccine ingredient) that was causing autism. When studies found no link between thimerosal and autism, the demands shifted again. This has happened over and over again for the last three decades, turning what was once a valid hypothesis into an unfalsifiable rumor that is designed to never die. When moving the goal posts is used, no amount of data is ever deemed “enough.”

See this video on YouTube, Instagram, or Facebook.

Straw man fallacy

The straw man fallacy occurs when someone misrepresents an argument to make it easier to attack. Instead of engaging with what was actually said, they oversimplify or exaggerate it, making it sound more extreme or simplistic than it really is. This fake version (“the strawman”) is easier to knock down, creating the illusion of winning the argument. But in reality, the original point was never addressed.

Examples of this fallacy in action:

“You said vaccines are safe, but clearly they have side effects!”

• Real claim: “Safe” means the benefits of vaccines outweigh the risks, and serious side effects are very rare.

• Straw man version: “Safe” means no risks of any side effects whatsoever.

“Doctors just want you to take a pill for everything.”

• Real claim: Chronic health conditions are complex, and sometimes diet and exercise alone are the best approach, while other times medications may be needed.

• Straw man version: Doctors just want to push pills for conditions that are really caused by poor diet and lack of exercise.

Communication tips for talking about fallacies

Prebunking by teaching these logical fallacies can be an effective strategy for helping people recognize unreliable health information. Here are a few communication tips to keep in mind when sharing these with your communities.

1. The goal is not to make people feel stupid. EVERYONE uses and falls for these fallacies from time to time, and they are not a sign of lack of intelligence. The goal is to empower people to identify and resist manipulation tactics, not to make them feel stupid. In general, shame-based messaging does not work, and it won’t work here.

2. Don’t just name the fallacy, explain the reasoning error. Naming the fallacy alone likely won’t help—the goal is to help people understand for themselves why the reasoning doesn’t hold up, so they can be equipped to identify the flaw in the future.

3. Provide real-world examples when possible. Hypothetical examples can be useful, but real-world examples help people see and understand these manipulation tactics in the wild, setting them up to identify them in the future.

Stay tuned for part three of this series, where we’ll dive into other rhetorical tricks that are commonly used to spread false health information. Subscribe below to follow along!

A version of this post was originally published on You Can Know Things.

Kristen Panthagani, MD PhD, is completing a combined emergency medicine residency and research fellowship focusing on health literacy and communication. In her free time, she writes the newsletters You Can Know Things and The Public Health Roundup. Views expressed belong to KP, not her employer.

Your Local Epidemiologist (YLE) is founded and operated by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE reaches more than 425,000 people in over 132 countries with one goal: “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now

Tick season is off to a bad start, a decrease in trust is pulling several diseases down with it, and the Pentagon just ended its flu immunization requirement. But there’s a lot of good news this week, too. Plus, we answer your questions on alpha-gal syndrome, a tick-triggered meat allergy.

Here’s what’s circulating and what it means for you.

Disease weather report

Ticks are unusually high

Well, it wasn’t a blip. Tick season really is off to an unusually bad start. Emergency department visits for tick bites are running at roughly 114 per 100,000 people per week, nearly triple the typical rate at this time of year (44 per 100,000). The Northeast is bearing the brunt of it, with the Midwest running a close second.

What this means for you: The main concern is Lyme disease (carried by black-legged ticks), but lone star ticks and dog ticks are also active and can transmit other illnesses, such as alpha-gal syndrome (see more below). There are many things you can do to prevent tick bites, and remember: nymphs are the size of a poppy seed.

Respiratory viruses are back to typical patterns

If you’re sick right now, it’s almost certainly a common cold. Rhinoviruses and enteroviruses dominate this time of year, and everything else—flu, RSV (which had a notably late season), and Covid—is finally declining for the first time in a long time!

What this means for you: Rest and fluids. (Yes, this really helps your immune system.)

Other diseases are increasing: Rotavirus and Vitamin K

Rotavirus (a contagious gut virus and the leading cause of severe diarrhea in young children) is generating headlines, with levels higher than last year. Wastewater monitoring shows a striking signal, though this monitoring technique is relatively new for rotavirus, making interpretation difficult. CDC test positivity rates (a more established metric) are modestly elevated compared to last year.

Why the uptick? Vaccination rates have declined gradually (74% compared to 77% in 2018).

But, as David Higgins notes, hesitancy alone likely isn’t the driver. Rotavirus vaccination is uniquely vulnerable to access barriers: The first dose must be given before 15 weeks, and the full series must be completed by 8 months. A child who loses Medicaid coverage, can’t find a pediatrician, or misses a single visit simply ages out of eligibility.

Vaccination data is delayed. So the current rates reflect children who should have been vaccinated in 2021, at the height of the pandemic-era disruption in care. Watching how these trends evolve alongside new access challenges, like Medicaid cuts, will be critical.

Vitamin K refusal shows concerning trends, increasing 77% (from 2.1% to 5.2%) from 2017 to 2024. This shot prevents Vitamin K Deficiency Bleeding (VKDB), a condition where newborns bleed spontaneously because they can’t yet produce enough clotting factors. The classical form affects as many as 1 in 60 to 1 in 250 unprotected infants. In other words, even a small increase in refusal translates directly into preventable harm.

What this means for you: If your child receives standard care (the routine childhood vaccination schedule and no refusal of the Vitamin K shot), they are very well protected. On a population level, we have a real problem. This will take all of us listening to questions, concerns, and confusion, answering questions from a place of empathy, and creating systems that make it easier (and more affordable) for people to access care.

Spotlight: Alpha-gal syndrome

We’ve gotten a lot of questions about alpha-gal syndrome from ticks lately, including a lovely snailmail note from a reader asking us to cover it.

What is it? A meat allergy triggered by a Lone Star tick bite. The tick introduces a sugar molecule called alpha-gal into your bloodstream. Your immune system responds. The next time you eat red meat, your body reacts.

Who is at most risk? The Lone Star tick is most common in the Southeast and South-Central U.S., but its range is expanding. For example, last year, there was an explosion of cases in the Northeast (Martha’s Vineyard).

Is alpha-gal actually increasing, or does it just feel that way? Both. Awareness has grown enormously in the last few years, which means more doctors are testing for it, and more cases are being caught that would previously have been written off as mystery GI issues or unexplained allergies. But the underlying cases are also genuinely rising. The lone star tick’s range is expanding northward and westward, driven largely by climate and deer population changes. CDC estimates there are around 450,000 cases in the U.S., but that’s almost certainly an undercount.

How would I know if I have it? The reaction is delayed two to six hours after eating, so by the time hives, stomach cramps, or nausea appear, most people don’t connect it to the meal. It can progress to anaphylaxis. People spend months thinking they have IBS or a sensitive stomach. If you have unexplained allergic reactions, especially delayed ones after meals, ask your care team about the possibility of an allergy.

Is it just red meat? Mostly. Beef, pork, lamb, and venison are the main triggers. Some people also react to dairy, gelatin, or mammalian-derived medications. Sensitivity varies a lot, which is part of why it’s so hard to diagnose.

Will I have this forever? Not necessarily. Some people regain tolerance if they avoid further tick bites, which is what prevents the immune system from re-sensitizing. Others don’t recover. No treatment exists beyond avoidance.

How do I avoid getting it? Take precautions against tick bites.

Good news

1. The South Carolina measles outbreak—the largest in the U.S. in 35 years—has officially ended, marking a significant milestone in containment.

2. Suicide prevention is working. A new study found that roughly 4,300 fewer teens and young adults died by suicide in the years following the launch of the 988 Suicide and Crisis Lifeline. Tell people about this resource.

3. A pancreatic cancer trial is showing real progress. Pancreatic cancer is one of the deadliest cancers because it’s caught late and responds poorly to treatment. Follow-up results from a very small phase 1 clinical trial testing a vaccine to treat pancreatic cancer showed that nearly 90% of people whose immune systems responded to the vaccine were still alive up to six years after receiving the last treatment. (Typically, the five-year survival rate is ~13%.)

4. Good news on dengue vaccines. A dengue vaccine trial kept every vaccinated participant out of the hospital over five years and reduced symptomatic infections by 65%. Dengue infects an estimated 100–400 million people annually worldwide.

Question grab bag

What is your take on the Pentagon recently ending its flu immunization requirement for active-duty military?

Here’s the deal: scientifically and economically, this new policy just doesn’t add up. I did some back-of-the-napkin math,1 and the military immunization requirement saves 30,000–98,000 duty days a year from the flu, which amounts to about $10-40 million in taxpayer dollars. This policy has been in place since the 1950s precisely because military readiness depends on keeping troops healthy and in the field.

But values and politics shape a huge portion of health policy. That’s what happened here. The performative political statement against vaccines as well as the intersection of individualism coming to the fore against the collective good.

If you have questions or requests, comment or email us at hello@yle.health. We read everything! And love to hear from you.

Bottom line

The weather is changing, trust is changing, and both are reshaping the diseases we face and how we protect ourselves. In the background, public health and research continue to fight to bring you good news.

Love, YLE

Your Local Epidemiologist (YLE) is founded and operated by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE reaches over 425,000 people in over 132 countries with one goal: “Translate” ever-evolving public health science so that people are well-equipped to make evidence-based decisions. This newsletter is free to everyone, thanks to the generous support of fellow YLE community members. To support the effort, subscribe or upgrade below:

Subscribe now