Thread by @michaelzlin

Posted today: Delta evades RNA vax too

6 of 100 vaxxed attendees at open-air wedding got sick.

In 2 with Covaxin, 1 (groom) died
In 4 with RNA vax, 1 hospitalized

All expected from measured 80% efficacy, yet PH officials say we don't need to worry.

disq.us/t/3yqfdib

Measured efficacy of 80% for RNA vaccines on Delta variant in the below paper. That's equivalent to 20% breakthrough rate relative to unvaccinated.

Remember this next time you hear someone claim vaccinated people can't get sick from COVID-19.

thelancet.com/journals/lance…

CDC advice that vaccinated should feel comfortable spending all the time they want indoors and unmasked with the 50% unvaccinated population while Delta surges through their communities doesn't sound so reassuring now, does it?

@michelleinbklyn you did the right thing

As the 4 RNA-vaccinated guests were symptomatic, you can be sure they're contagious too.

Note CDC stopped asking states to collect data on non-severe vaccine breakthroughs. So if these study authors had followed the CDC, they would have just reported the 2 hospitalized patients

Also today, Pfizer RNA vaccine found to be only 70% effective in Israel study (compared to 88% in England and 80% in Scotland)

timesofisrael.com/liveblog_entry…

Correction: Fatal case was not the groom, or at least not specified as the groom. Thanks to @gshashank9798 for pointing out my mistake.

@gshashank9798 BTW goes without saying that outcomes would have been much much much worse if 40% of the people at the wedding were not vaccinated (the US national average). We need to get >85% vaccinated to reach herd immunity, but until then, the already vaxxed need to exercise caution.

DeSantis spokesperson defending Florida's don't ask policy: "It’s almost unheard of for a vaccinated person to get seriously ill with Covid-19. Therefore, people who are vaccinated should not be worried about getting infected from those who aren’t.”

So CDC that's what happens when you tell people that serious breakthroughs are very rare. You give the unvaxxed another rationalization why they don't need to get vaccinated.

It's now official: Israel says Pfizer efficacy is 64% for symptoms from Delta, lower than the UK's 88%. 93% for severe disease.

Maybe reassuring if everyone around you is vaxxed and healthy. Not so fine if you care for someone unvaxxed or sick.

usnews.com/news/world/art…

Now say we average out the various measures of Pfizer efficacy on Delta (88% England, 80% Scotland, 64% Israel) to get 77%. We can then estimate that instead of 4 vaxxed people getting sick, there would have been 4/0.23 = 17 people sick if nobody at the wedding were vaxxed.

Many are asking if the 64% is symptomatic disease only or all infection including asymptomatic.

It's each.

https://twitter.com/michaelzlin/status/1412201744918974465