Thread by @VincentRK

A large seroprevalence study found that we may be underestimating number of COVID cases in the US by 10-fold. What does this mean?

Thread/

1) First, this is a great study. Read the original article if possible. @JAMAInternalMed @CDCgov jamanetwork.com/journals/jamai…

2) Second, here is great summary by @Scatter_Cushion @TheScientistLLC google.com/amp/s/www.the-…

The main point is that despite the fact that we are underestimating the number of cases, even in these area that were quite badly affected by COVID, the seroprevalence is less than 10%.

3) Even in New York, which was one of the worst affected in the US, seroprevalence is only 6.9% of the population. It is a long way away from herd immunity. Trying to get to herd immunity without a vaccine is not good policy. @ASlavitt @CarlosdelRio7 @PSampathkumarMD @choo_ek

4) In all other places studied, the seroprevalence was much lower than NY. Most of the rest of the US will be even lower than these paces studied. Again we cannot wish our way to herd immunity. It will cost a lot of lives.

Full table below. @JAMAInternalMed

5) I have stated that seroprevalence may itself underestimate true exposure rate & % of susceptible population. But even that would only double the seroprevalence estimate. Not more than that.

If we doubleseroprevalence, it still leaves >90% population susceptible. @DrEricDing

6) So while we maybe seeing a drop in cases in major hotspots due to a variety of factors (see linked article) we have to recognize that >90% are susceptible & so we need to continue preventive measures till we have an effective vaccine. @JoshuaPCohen1 google.com/amp/s/www.forb…

7) In fact, many countries in Europe with the level of seroprevalence as NY are already having 2nd waves. While the mortality and ICU admission rate in these 2nd waves appears lower, it is too early to be sure. People are still dying of COVID, & there are long term complications.

8) Preventive measures doesn’t mean endless lockdown. It’s a false dichotomy between lockdown and pre-COVID times. What’s needed is we avoid crowds and crowded gatherings especially indoors, social distance as much as possible, wear a mask, hand hygeine, & be careful and patient.