LOL Grandpa Drudge, I was just going back over stuff from last year and found the below, dated Sep. Yor article is dated Nov, which just goes to show, we couldn’t get straight info even back then!
Conclusions and Relevance This cross-sectional study found that as of September 2020, most persons in the US did not have serologic evidence of previous SARS-CoV-2 infection,”
https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2773576
Note: in your link it was already up to 23% (very high for then, early) in New York, where the most rapid rates of death were occurring at the time.
Incredibly, that's just when the CDC went off the rails and stopped tracking (or at least stopped reporting) this most important data.
I have a very strong suspicion that was deliberate on CDC's part.