Thread by @sailorrooscout

I thought it was vital to bring this up as I am seeing this study circulate and being used in a lot of media today concerning Brazil’s variant P.1. Most of the misinformation over Brazil’s variant P.1 appears to stem from a single, unreliable serological survey in Manaus. 🧵

We can see the media has latched on to a study which claimed Manaus had reached herd immunity due to 76% of its population being previously infected with SARS-CoV-2. The claim was based on flawed serology data- its likely they never did. We now see that any reference to Manaus is

laced with fear of reinfection, despite there being no evidence of this on a larger scale. A follow-up study that received less publicity found that their peak was more like 15% rather than 76% that was being circulated and claimed.
thelancet.com/journals/langl…

For one, this study here is solely based on modeling and has been circulating through a lot of media in Brazil as well as the UK, and data (or lack there of) unfortunately was based on a prior modeling study that was debunked (the 76% issue you see discussed above and below).

https://twitter.com/CaddeProject/status/1365465206302920710

The previous study was debunked last year here by Wes Pegden. Please do be sure to read this thread in its entirety as it is extremely informative.

https://twitter.com/wespegden/status/1336801382955933697

Thanks to the wonderful @stevebrown2856, as he states, “we can see the study hypothesizing high rates of reinfection used a modeling approach based on high fatalities and calibrated against the 76% prior attack rate, meaning it is likely flawed. The whole study falls apart with a

lower prior attack rate.” Furthermore, “the idea is that because the 1st wave in Manaus was apparently so large, the 2nd can only have occurred with significant reinfections. However, if the 1st wave was much smaller (but with high fatalities because Manaus ran out of oxygen)

the logic falls apart.” From what we are seeing, it seems the issue lies within Manaus collapse of its healthcare system during the 1st wave, making reinfection seem much more severe than it really was and a sense of false security come the 2nd wave. With new preprints today

we are seeing that P.1 is proving to be less of a threat than B.1.351 and B.1.1.7 and that the vaccines stand to be protective against this variant which can be seen here:

https://twitter.com/sailorrooscout/status/1367094490121568263

The point I am attempting to address is that, while a VOC, P.1 is something that is within our grasp of controlling and I just wanted everyone to be certain of the flaws of the study circulating in the media. Special thank you to @stevebrown2856, @davidbautistaqf and @guto7776.

I was up for quite some time last night sifting through studies and newspaper articles and I was tired of seeing people having to be thrown into a panic with little understanding so hopefully this helps today.

Also, so everyone understands, once again, in trying to clear up misinformation, my intentions are never to “trash” anyone’s research. I was trying to point out discrepancies that have led to a lot of misunderstandings and confusion. I’m not looking for a “gotcha” moment.