A Bad Number in A Good Cause: A Scientist’s Plea About COVID Vaccine Numbers

A screen capture of Fox News touting vaccine success.

I’ve lately been seeing a lot of tweets, news segments and articles talking about the success of vaccination and using COVID vaccine numbers like this:

Of the 164 million vaccinated Americans, less than 0.1% have been infected with the coronavirus, and 0.001% have died, according to data from the CDC.https://t.co/qPAJW35tIJ pic.twitter.com/yCveWpz7jb

— Axios (@axios) July 31, 2021

I am going to ask folks nicely: please please please please please stop putting out numbers like this. Without context, it is absolutely meaningless. It is exactly the same thing the COVID deniers did last year when, while the pandemic was just getting started, kept saying, “Hey, COVID has only killed a few hundred people, why are we panicking?” In fact, you could have reproduced this exact number for unvaccinated Americans if you ran it in April 2020.

The Delta infection has just hit our shores. It is still spreading. Fortunately, the vaccines appear to be effective in preventing infection, hospitalization and death. But more vaccinated people are going to get infected. More are going to be hospitalized. More are going to die. That’s simply a fact. And so, the numbers cited above will keep changing.

Now if you want to compare these numbers to unvaccinated Americans, that is useful information. About 100,000 Americans have died since we began mass vaccination and only 1000-2000 of those were vaccinated. The vast majority of those who died were not fully vaccinated. That’s useful information. But it’s also fraught. Because most of those deaths were due to the original COVID strain. Delta may change the math quite a bit so that a much larger percentage of deaths are among the vaccinated (and the percentage of the unvaccinated dying will rise anyway as more people are vaccinated due to a statistical illusion called base rate bias).

I used deaths as a comparison because the number of infections among the vaccinated is almost certainly useless. Vaccinated people are far less likely to develop symptoms and far less likely to develop severe symptoms. So, they are less likely to get diagnosed with COVID in the first place.

Look, the case for vaccines is clear. And I’m glad to see reports of vaccinations ramping up over the last week or so as people realize that we’re not out of the woods. But boasting that the vaccinated aren’t getting sick…yet…smacks of hubris. And if the pandemic has taught us anything, it’s to be cautious in proclaiming victory.

In the meantime, in one of our “read it for yourself” things, I’ll link you to the CDC’s internal documents on the Delta variant. The short version is that Delta is far more infectious. And while the vaccinated are far less likely to get the disease, if they do get it, they are just as likely to spread it as the unvaccinated. Which is why masks are coming back. There’s also a good case to be made for booster shots, especially for those whose immunity comes from a prior infection instead of the vaccine.

It’s important that we continue to be cautious with COVID vaccine numbers. But we should also continue to know hope. We’re making progress. But the war isn’t over.