India must be being protected by cross reactive immunity from prior corona viral infections.

Let us examine the data:

1)>2.7 million diagnosed with COVID.

2) Seroprevalence in hotspots:
Mumbai slums 57%
Pune 52%
Delhi 29%

3) Much lower mortality than expected. @nramind

4) There is decrease in new cases in Mumbai & Delhi.

5) Mumbai and Delhi hospitals have not had the overflowing ICUs & ERs seen in Lombardy or NY despite far less resources.

6) Tens of millions live in situations where social distancing is impossible. Explains seroprevalence

7) Talking to friends Mumbai is slowly returning to normal.

8) With this level of seroprevalence the mortality rates if similar to the US should be far far higher. But it’s not.

This is the puzzle. Something is happening that we must try & understand more. What’s happening in India suggests some protection from severe disease being afforded by cross immunity from prior corona viral infections. @rfsquared @Rfonsi1 @DrEricDing @GargiRawat @PSampathkumarMD

As I have said before cross reactive immunity and T cell responses may not be able to protect from infection. But can protect from severe disease and lower ICU rates and mortality. I think this is what is happenning.

It could be genetic predispositions. But much less likely.

IMPORTANT: This does not mean it is safe in India. Hundreds of millions remain susceptible. Countless people have become critically ill. >50,000 reported deaths.

Too many lives will be lost if you are not careful.

PLEASE
#Masks4All
Social distance
Hand hygeine

DONT RELAX

Links. Delhi seroprevalence https://twitter.com/gargirawat/status/1296394478610051073

Pune. @the_hindu https://www.google.com/amp/s/www.thehindu.com/news/national/other-states/515-people-in-pune-have-developed-antibodies/article32379627.ece/amp/

Dharavi and Mumbai. https://www.google.com/amp/s/www.thehindu.com/news/national/coronavirus-57-of-mumbai-slum-population-has-developed-antibodies-study/article32216939.ece/amp/

Lots of factors that could be playing a role.

-Undercounting of deaths
- Lower age
- Lesser obesity

But there are also factors going the other way

-Overcrowding
- Poverty
- Less hospital resources

My judgment is that there is more going on that we need to understand.

My prior thread on the 4 Major reasons why severity of the disease may be low in some people. https://twitter.com/vincentrk/status/1294404193294442502

Re: Is it possible that deaths are being undercounted? https://twitter.com/vincentrk/status/1296430507878764544

Some have commented on BCG, summer temperatures, and Vit D.

I’m not sure. From what I’ve read so far, I doubt these are playing a role.

Oh. The one thing I’m sure is that it’s not HCQ. We have studied that drug in randomized trials. It doesn’t work. Period.