What to expect from this week's U.S. vaccine meeting

Hep B, routine vaccination schedule, and a firehose of falsehoods

Well, folks, buckle up.

Tomorrow, ACIP—the advisory committee that guides U.S. vaccine policy—meets again for two days. This group has enormous influence on your access to vaccines: its decisions shape vaccine supply, insurance coverage (including Medicaid), clinicians’ understanding of what to offer you, how many doses hospitals and pharmacies stock, and the public’s confidence in what, where, when, and how to get your vaccines.

This meeting will focus on two things:

1. Hepatitis B vaccine, including a vote that could meaningfully affect infant access in the U.S.

2. The entire childhood immunization schedule, including its history, the number of doses, ingredients like aluminum, and whatever else they may pull out of their hat.

It’s going to be a ride. Mainly because a few months ago, RFK Jr. overhauled the committee, replacing long-standing experts with individuals ranging from longtime vaccine skeptics to Covid-19 contrarians.

So, here’s your guide to what to expect, including a proactive heads-up on the misleading claims likely to surface and a breakdown of the fallacies behind them. Whether you’re a clinician answering questions, a parent scrolling social media, or simply someone trying to find clarity in the chaos, I hope this is helpful.

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Note: As I shared with paid subscribers yesterday, together with The Evidence Collective (TEC), we wrote a much deeper pre-bunk HERE that includes key background on all anticipated ACIP topics, practical communication guidance, a fallacy playbook, and a rundown of the falsehoods and rumors likely to surface. Below is a high-level summary.

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What to expect

Credible sources suggest none—or very few—of the ACIP presentations will be delivered by CDC scientists or experts. Instead, external groups, including some with clear anti-vaccine track records, are slated to take the lead. This is highly unusual, and I’m incredibly concerned that data will be misinterpreted and misleading, and false claims will be presented as expert testimony.

Reviewing the timing, spacing, and risks of each vaccine requires scientific expertise because the stakes are high: get the evidence or timing wrong—or lose sight of the historical reasons behind these recommendations—and preventable diseases can come roaring back. And once falsehoods are aired in this forum, they can spread quickly, potentially amplified by one of the nation’s highest offices.

But there is good news.

1. There is no vote for the childhood vaccination schedule as a whole. They will only discuss it. This means timing, spacing, and availability to you won’t change. The only vote is on the Hepatitis B vaccine, specifically whether to maintain the universal birth dose given within 24 hours of life.

2. We know exactly what to expect. These players have relied on the same falsehoods and logical fallacies for decades. Their playbook hasn’t changed. That means we can prepare.

Thursday’s vote

The only vote tomorrow is on whether to keep the universal Hepatitis B birth dose, given within 24 hours of life. At September’s meeting, RFK Jr.’s ACIP proposed delaying it for infants born to mothers who test negative. This decision could significantly affect vaccine availability for infants and increase the overall number of infections.

Why the universal birth dose exists:

• Babies are especially vulnerable—9 in 10 infants who catch it become chronically infected

• 12–18% of U.S. pregnant women are never tested for hepatitis B.

• Only 35% of women who test positive get recommended follow-up care.

• The birth dose catches babies who fall through those cracks.

What the evidence shows:

• No safety, efficacy, or long-term benefit to delaying.

• Delaying to 2 months: 1,400+ additional infections, 480+ deaths per birth year.

• Since 1991, the birth dose has cut pediatric hepatitis B infections by 99%.

: Reported number of acute hepatitis B cases in the United States by year, 1980-2023 and related policy milestones. Figure by CIDRAP. Annotated by Your Local Epidemiologist (red)

The birth dose exists precisely because screening isn’t perfect. The evidence doesn’t support changing that.

Then onto Friday

On Friday, the agenda is unusually broad: the entire childhood vaccination schedule. I expect it to be a waterfall of falsehoods. Here is some clarity on the topics they are likely to cover.

1. How the vaccine schedule is built—and why it exists

The childhood vaccine schedule isn’t new. The American Academy of Pediatrics (AAP) first introduced it in 1938, when just four vaccines existed: smallpox, diphtheria, pertussis, and tetanus. Those few vaccines alone prevented tens of thousands of childhood deaths each year. Over the following decades, the addition of vaccines for polio, measles, mumps, rubella, and others drastically reduced childhood illness, disability, and death.

Many diseases on today’s schedule are now rare because of vaccines. For example, once Haemophilus influenzae type b (Hib) vaccine was added in the late 1980s, cases of severe childhood meningitis and epiglottitis dropped 71% within two years. These diseases disappeared from everyday experience, not because they stopped existing, but because the schedule worked.

In 1995, AAP and ACIP created a unified national schedule, ensuring children across the country received consistent, science-based protection. Today, the schedule protects against 17 diseases. Each year, an updated version is published on CDC’s website.

2. Why vaccines are given when they are

The schedule is designed to protect children from dangerous infections as early as possible, while spacing doses to create the strongest immune response.

• If given too early, maternal antibodies can interfere with some vaccines, or the child’s immune system may be too immature to build long-lasting protection.

• If given too late, children remain vulnerable during the period when their risk of severe disease, hospitalization, or complications is highest.

Diseases like pertussis, measles, and pneumococcal infection are especially severe in infancy and early childhood. The schedule reflects decades of research into the biology of both children’s immune systems and the pathogens themselves.

Further spacing out vaccines doesn’t provide extra safety; it extends the window of vulnerability and makes families less likely to complete the schedule.

3. Do children get “too many” vaccines?

People hesitant about childhood vaccines often claim children receive 72 or 96 doses, but these numbers are misleading.

Children receiving vaccines according to the current schedule receive about 54 doses over 18 years, protecting against 17 diseases. And a third of those are yearly flu vaccines. Misleading and inflated counts might include every yearly flu and Covid-19 shot, count combination vaccines (like MMR) as separate vaccines, or count vaccines given to pregnant mothers. The exact number varies based on timing, catch-up schedules, health conditions, and available formulations.

Our immune systems can’t be overwhelmed, either. Today’s vaccine antigens represent a tiny fraction of what immune systems encounter daily from normal environmental exposures. For example, young children average up to 8 to 12 colds per year. Routine infections stimulate strong immune responses—thankfully, that’s how we recover from illness. Children’s bodies are made to respond and learn from what they’re exposed to, and are not “overwhelmed.”

It’s true that children born before the 1990s received fewer vaccines than today’s kids. But over the years, we’ve exposed children to fewer and fewer antigens (parts of microbes that stimulate the immune system) while protecting against more diseases. Because we target immune protection far more efficiently. In the mid-1980s, children were exposed to 3,000 antigens in vaccines. Now it’s 180.

Figure made by Your Local Epidemiologist

4. Has the entire vaccine schedule been studied?

Hundreds of studies have examined the safety of individual vaccines and common combinations, but few have evaluated the entire childhood immunization schedule. Studies in other countries that have similar vaccination schedules have found no red flags:

• A German study compared disease rates among kids who completed the vaccine schedule to those who didn’t. As expected, unvaccinated individuals have a much higher rate of vaccine-preventable diseases.

• A U.K. study of nearly six million childhood vaccine doses found that administering vaccines according to the schedule is safe—any increase in reactions was limited to mild, temporary effects such as fever.

Ethical and feasibility considerations constrain research to the fullest extent. Randomized trials assigning children to delayed or no vaccination would require withholding proven protection, which is unethical. We continually evaluate safety through trials of each new vaccine, during which children receive the full existing schedule, effectively testing the schedule and the new product. Regulators require additional “concomitant use” studies to assess how vaccines interact when given together, ensuring they are tested in the same combinations and at the exact timing used in real life.

5. Aluminum, ingredients, and other familiar targets

Aluminum has been used safely in vaccines for more than 90 years.

Trace amounts of aluminum in shots strengthen the immune response, helping the body develop better protection. It allows vaccines to use smaller amounts of antigen and reduce the number of doses needed.

Fortunately, we have recent and high-quality data showing this is safe. A recent Danish study examined more than 1.2 million children born between 1997 and 2018, following them for up to 24 years—one of the largest vaccine safety studies ever conducted. Researchers analyzed 50 different conditions: autoimmune, allergic, and neurodevelopmental, including autism and ADHD. They tested whether greater aluminum exposure was associated with a higher risk of disease. They found no evidence of harm, no dose-response relationship, and no increased risk for any of the 50 conditions studied.

There are other options. (Currently, five adjuvants are available on the market.) However, companies would need to develop new vaccine formulations with alternative adjuvants and conduct new clinical trials. This would be expensive and difficult on a practical level (recruiting enough participants, getting enough cases of disease to determine whether the vaccines actually work as well or better than the aluminum-adjuvanted ones, etc.). Furthermore, aluminum adjuvant is already preferred in childhood vaccines because it tends to be much better tolerated than other adjuvants.

How to recognize the playbook

It’s impossible to anticipate each potential misleading or false claim that may emerge this week. DNA fragments in vaccines will likely come up. Autism almost certainly will. Responding to vaccine falsehoods and rumors, as we’ve done here, can feel like whack-a-mole—refuting one false statement after another in a never-ending cycle. So, while we work to debunk specific claims, it’s equally important to understand the underlying tactics. Recognizing patterns will help us all be more discerning, regardless of the topic.

Watch for:

• False authority (non-experts framed as experts)

• Appeal to fear (magnifying tiny risks, minimizing bigger ones)

• Correlation ≠ causation

• Cherry-picking (one flawed study vs. dozens of high-quality ones)

• Moving goalposts (“if it’s not thimerosal, then aluminum… or DNA…”)

• Reversing the burden of proof (demanding that others disprove a claim instead of providing evidence for it)

• Anecdotes as evidence

• Naturalistic fallacy (“natural immunity is better”)

• False balance (“both sides” even when evidence is lopsided)

These tactics matter because they’re designed to confuse, overwhelm, and erode trust. Not inform.

Bottom line

These vaccine policy meetings have real-world consequences—for your access to vaccines, for how diseases show up in your community, and for the rumors and falsehoods that will inevitably flood social media, podcasts, and other information spaces.

We’ll be back with Cliff notes from the meeting and, most importantly, what it all means for you.

Love, YLE, Unbiased Science, and The Evidence Collective

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Your Local Epidemiologist (YLE) is founded and operated by Dr. Katelyn Jetelina, MPH PhD—an epidemiologist, wife, and mom of two little girls. YLE is a public health newsletter that reaches over 400,000 people in more than 132 countries, with one goal: to translate the 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.