Thread by @EricTopol

Why is "I'm vaccinated, I'm fully protected" wrong?
The pivotal clinical trials, such as with mRNA vaccines, showed a 95% reduction of symptomatic infections, the primary endpoint. Not 100%
That was pre-Delta
nytimes.com/2021/07/22/hea… @apoorva_nyc /1

Now we have conflicting data for protection vs symptomatic infection post-mRNA vaccination for Delta
UK @NEJM 88% protection

https://twitter.com/EricTopol/status/1417955897087725569

Israel 40% protection (unpublished)
bloomberg.com/news/articles/… /2

We don't have an explanation for this glaring contradiction, which could include demographics, sample size, time from vax, all sorts of things. The delayed 2nd UK dose (8 wk) has been suggested by raising level of immunity. But we don't know yet /3
bbc.com/news/health-57…

It is clear that post-vaccination Delta infections are more common than prior versions of the virus, such as this preprint from yesterday /4 medrxiv.org/content/10.110…

There is certain risk for infection Delta post-vaccination, even with the most potent vaccines, although the level of risk is uncertain (between 39-88% protection so far. The risk for severe illness (incl hospitalization/death) is extremely low (<-can't be emphasized enough) /5

So as @ASlavitt reviewed in his excellent thread last night, avoid what I call a Delta stress test for your vaccine- induced immunity, wear a mask indoors until this wave clears and there's low levels of virus around /6

https://twitter.com/ASlavitt/status/1418428400574681090