Variants in the U.S.

And why it's important.

Is there a variant surge?

We think so. The picture is messy, but here’s my best attempt…

It’s a difficult question to answer.

We can’t identify the variant for every COVID19 test. In order to do this, we would need a lot of technology, a lot of time, and a lot of money. The US just doesn’t have the infrastructure to make this possible right now.

So, we have to pick which COVID test gets analyzed. But this isn’t systematically done. First, we need a site that has the capability to identify variants (usually hospitals or universities). This isn’t as common as you would think. In Texas, for example, with a population of 29 million, we have 3 labs that can detect variants. And, even if a state has a site, we then need to pick which individual tests get analyzed. Because of this, it’s nearly impossible to get a “true” picture of variant spread in the US. It’s likely a biased picture.

Nonetheless, we need to pay attention to the % of new cases that are variants of concern

Why? We’ve started seeing a pattern. Once variants (like B.1.1.7) accounts for 50-60% of cases in an area, a surge begins. This is true regardless of vaccination rate (for now).

This was apparent in the UK. On December 21, 2020, 62% of UK cases were B.1.1.7. And, at this time, the UK was already well on its way to a surge.

This was apparent in Italy… On Feb 22, 2021, Italy had 60% of B.1.1.7. This was right before their surge, which was slowed down due to lockdowns.

Interestingly, this was also apparent in Israel, despite their vaccination rates. On Jan 25, 2021, 62% of Israel’s cases were B.1.1.7. Also at this time, a surge started. On Jan 25, 31% of their population was fully vaccinated. This is important to know. It doesn’t look like vaccines have an impact on population numbers until ~57% of the population was vaccinated.

Are variants causing the 4th wave in the U.S.?

We assume so. Mainly because B.1.1.7 is creeping up close to 50-60% of our cases. Our surveillance system, albeit less than perfect, is showing high rates of B.1.1.7 from multiple sources…

  1. This week, the CDC reported that more than 50% of new cases are now B.1.1.7 in the United States. From what I can tell, this is based on a consensus of anecdotal hospital reports and projection data. Unfortunately, their public use data is severely lagged. On March 13, B117 made up 27% of cases. So, if B117 has a doubling rate of 6.9 days, we should be at a much higher rate today.

  2. We can also pull data from NextStrain, which estimates about 30% of U.S. cases are of B.1.1.7 today. Nextstrain is a system that tries to summarize all genomic across the world. (And, yes, the colors are absolutely terrible, but we couldn’t do anything about that).

Today 5 states account for more than 45% of cases overall: New York, Michigan, Florida, Pennsylvania and New Jersey. In fact, Michigan’s wave 4 is almost as high as its Wave 3. These states also happen to have some of the the highest B.1.1.7 levels reported by the CDC. Is this a coincidence? Probably not.

Hospitalizations are increasing too

Which makes sense. Despite many older populations now being vaccinated, B.1.1.7. is more severe and deadly. So, younger populations who wouldn’t have gone to the hospital before, will go now.

Should we worry about younger populations?

Yes. Younger adults and kids seem to be spreading the variants. Unfortunately, though, we don’t know whether it’s due to the actual variant being able to get into kids cells easier OR because of behaviors (going to school, etc).

  1. Transmission has always been higher among younger populations. That’s what’s driven the pandemic. Right now, test positivity rate for younger populations are incredibly high. They just don’t get tested, so they are more likely to spread the disease.

  2. Younger populations (under 45) have the highest rates of vaccine hesitancy and/or not worried, so they are just not getting the vaccine.

Bottom line: B.1.1.7. is something to worry about. It’s likely causing our surge. Vaccine rates are not high enough to protect our community yet. Stay vigilant. And get that vaccine.

Love, YLE