Weeks ago there was a report that 13.7% of pregnant women admitted during labor in NYC tested positive for covid-19. That was using a PCR test, not an antibody test, IIRC. That surely implies that weeks ago the rate of infection in the city was at least 13.7% minus false positives plus what would have been antibody test positive patients who were not producing the virus any longer. To go from ~13% to 21% in a few weeks seems perfectly reasonable. Moreover, "suggest" is a bit of a weasel word: there's no proof, only statistical approximation. So, yes, I suspect the city really is at 21% exposed.
> The only actual good indicator we have is the rate of change of deaths and hospitalizations.
Nonsense. The right thing to do is to perform randomized antibody testing of the population. The sample has to be random. The city (and other cities, and States) should pick an appropriate number of household addresses randomly, send techs and police to each one, pick a random person at each address, and test them. Given a sufficiently random and representative sample, you don't need to test so very many people to determine with a very high degree of certainty just how much of the population has been exposed.
Only then can hospitalizations and deaths be put in perspective. If SARS-cov2 spreads through enough of the population to reach "herd immunity" and its ultimate impact is, as I expect, much less than a bad normal-flu season, then the shutdown was not necessary and should stop (not necessarily other protective measures).
On the flip side, if very little of the population has been exposed to covid-19, and we were to stop the shutdown due to declining death and hospitalization rates, then the risk would be very high of a second wave.
Randomized antibody testing is absolutely essential here. We need to know how it progresses through the population, and we need to know ASAP.
> The only actual good indicator we have is the rate of change of deaths and hospitalizations.
Nonsense. The right thing to do is to perform randomized antibody testing of the population. The sample has to be random. The city (and other cities, and States) should pick an appropriate number of household addresses randomly, send techs and police to each one, pick a random person at each address, and test them. Given a sufficiently random and representative sample, you don't need to test so very many people to determine with a very high degree of certainty just how much of the population has been exposed.
Only then can hospitalizations and deaths be put in perspective. If SARS-cov2 spreads through enough of the population to reach "herd immunity" and its ultimate impact is, as I expect, much less than a bad normal-flu season, then the shutdown was not necessary and should stop (not necessarily other protective measures).
On the flip side, if very little of the population has been exposed to covid-19, and we were to stop the shutdown due to declining death and hospitalization rates, then the risk would be very high of a second wave.
Randomized antibody testing is absolutely essential here. We need to know how it progresses through the population, and we need to know ASAP.