Biotech Values

[JohnWayne]

The comments in the original tweet by @Ananyo with the BMJ article do a good job poking holes in the optimism about higher than expected asymptomatic rates.

Boils down to the distinction between 1) asymptomatic at time of viral detection vs. 2) asymptomatic over the course of the infection & viral clearance. The China data would be indicative of 1), but this in itself doesn't suggest that "the cure [lockdowns, economic disruption] is worse than the disease", as the larger body of data suggest that 2) happens only in a minority of cases, i.e. most patients who are asymptomatic at the time of detection become symptomatic with more follow-up.

A couple references:
[url]https://www.cdc.gov/mmwr/volumes/69/wr/mm6913e1.htm?s_cid=mm6913e1_w
[/url][tag]Kirkland SNF CDC report.[/tag] Shows that 57% of +ve cases were asymptomatic at diagnosis (n=13/23) but of these 13 cases, only 3 remained asymptomatic 1 week later. So, 3/13 (23%) who were asymptomatic at diagnosis remained so, and only 3/23 (13%) of all positive cases were "true" asymptomatics (though presumably could have become symptomatic with >1 week of follow up). Given this is a SNF with a high-risk population, it may not be generalizable

Chinese study of 55 asymptomatic patients admitted to a hospital due to contact with an infected family member. 40% of these cases were >50 years old, 31% were 30-49 years old, and 27% were <18 years old. Only 2% were 18-29 years old, which is perhaps surprising and maybe also undercuts the theory of widespread asymptomatic infections... The paper is a bit hard for me to follow, but I think it looks like n=16/55 (29%) remained asymptomatic during hospitalization, which is actually pretty consistent with the 23% result from the Kirkland SNF study.

I believe the Diamond Princess experience had similar results but don't have that handy right now. There are probably other studies as well, but from what I've seen it doesn't seem like we should expect widespread asymptomatic, undetected infection to 'save us' or build herd immunity, as these cases will most likely become symptomatic given a week or two.