Thread by @joshmich

Important data on "breakthrough" infections: CDC says 5,800 infections documented so far in the US, of which 396 (7%) needed to be hospitalized. About 77 million people have been fully vaccinated in the US.
cnn.com/2021/04/14/hea…

CDC says a "little over 40% of the infections were in people 60 or more years of age" but hard to draw too many conclusions from that given that the preponderance of the vaccinated are in that age group, too.

We knew these infections would occur, and that some could lead to severe disease and even death. In this article alone, three different experts used the phrase "not surprising" to describe the phenomenon. Vaccines are not 100% protective.
washingtonpost.com/health/2021/04…

So one nitpick with the CNN story linked first: the article states the CDC data is "the first indication the vaccines do not protect completely against severe disease and death," when that is not the case

We've had previous real world data that breakthrough infections, including those leading to severe disease and hospitalizations, were occurring among fully vaccinated people. For example, Israeli studies like this one
nejm.org/doi/full/10.10…

Important to keep in mind, though, that when these breakthrough infections do occur, the evidence indicates they’re "not as bad as they would have been had the person not been vaccinated" in most cases.
vox.com/science-and-he…

And, "the number of breakthrough infections that accumulate depends on how much virus is out there circulating in the community" so important to continue to reduce transmission through vaccines and non-pharmaceutical interventions, which makes such events even rarer.

Some context from Israel - the apparent proportion of breakthrough cases really is very small

https://twitter.com/EricTopol/status/1382550255195987969?s=19