[nradov]

The official case numbers in Japan probably drastically undercount the number of infections due to limited testing. A recent antibody seroprevalence study found 46% positive. It wasn't a truly random sample but had a large study population from multiple locations. If mask wearing is such a big factor than how did so many people get infected?

https://www.medrxiv.org/content/10.1101/2020.09.21.20198796v...

[lern_too_spel]

Because Japan's population is so elderly, any severe undercount of infections would show up as very large excess mortality, but that hasn't been observed.

[nradov]

Then how do you explain the study results linked above?