Gloria in excelsis deo, we are finally getting data on how much of the new coronavirus is out there (the virus’s official name is SARS-CoV-2, the disease it causes is COVID-19, that’s a mouthful for the politically correct, but Wuhan flu or Chinese is also accurate and is at least easier to pronounce). We now have two studies from California (LA and SF) in which the prevalence of antibodies to the virus is around 4% (https://www.latimes.com/california/story/2020-04-20/coronavirus-serology-testing-la-county — 3 days earlier the SF study said the same thing).
The presence of antibodies to the virus means that the individual has been infected with it, and has probably fought it off, as these people were picked in a random sample and were not hospitalized. This is hundreds of thousands of people in each city.
That’s not enough for herd immunity, BUT — insert happy thought here
What if the 96% of the population not showing the antibodies were exposed but didn’t get the virus? Suppose that previous colds had given them immunity (as I proposed in an earlier post — https://luysii.wordpress.com/2020/04/05/a-way-to-end-the-pandemic/).
Then the epidemic in the USA, horrible as it’s been, has peaked. Certainly the number of cases in hospitals in NYC has stabilized, and they’re shipping respirators to NJ.
How would you know? Just repeat the study each week. If the percentage of people showing antibodies remains the same, those who are going to get the virus have already gotten it. It seems inconceivable to me that with hundreds thousands of people in LA and SF unknowingly wandering around before social distancing, they haven’t already spread it to all and sundry.
As always, there are caveats about this. The main one is the accuracy of the antibody test — specificity primarily — are the antibodies just to the new coronavirus or are they picking up other things. Hopefully not, and Stanford (who did the study) should be state of the art.
Very much against the idea, is the lack of immunity among the vulnerable — it spread like wildfire through the Soldier’s Home in Holyoke, Mass. The statistics are truly ghastly. There were 210 vets living at the home. 52 have died due to COVID19, 94 are alive but positive for the virus, so 69.5% of the vets have been infected.
Chemiotics II 
Comments
It may be that if you are hit by a low virus dose at first, you have time to build immunity. If you are hit with a high dose at first, if the disease don’t get ya, the cytokine storm will.
If the soldiers’ home was under strict quarantine, the first entry might have been low or high, but in a confined space, one might expect subsequent infections in the home to be high. In other words, a group quarantine of a susceptible population might lead to excess deaths, compared to isolating the susceptible individuals.
So it’s possible that this is not really an unexpected pattern even if on the outside, people have gotten low doses and are immune.