[SpicyLemonZest]

I found the paper they're referring to [1], and it's just trivially wrong. The authors argue on pages 9-10 that:

* Infection rates calculated from seroprevalence surveys are consistently at least 10 times higher than the number of infections confirmed through PCR tests.

* In Zhongnan Hospital, 2.88% of the workers got positive PCR diagnoses, which means we expect the true infection rate is above 25%.

* The seroprevalence survey of Zhongnan hospital showed only 4%, so the other 20% must have not developed antibodies.

But that third bullet doesn't make any sense! The 10x multiplier is an expectation based on seroprevalence surveys - a lack of antibodies doesn't actually explain the discrepancy. (To flip it in the other direction, if it's really true that only 4/25 of patients develop antibodies, NYC's 20% seroprevalence rate means 320% of the city's population has caught the virus.)

[1] https://www.medrxiv.org/content/10.1101/2020.06.13.20130252v...