1/ INCREDIBLE STUDY:

615 adults in Tokyo were prospectively recruited to take Sars-Cov-2 antibody tests.

When the study began 6% had antibodies, indicating exposure.

By mid-summer 47% did. Half the population.

Not one person was hospitalized or died...
https://www.medrxiv.org/content/10.1101/2020.09.21.20198796v1.full.pdf

2/ BUT WAIT THERE'S MORE:

Many IgM antibody tests rapidly reverted to negative after being positive. So point-in-time antibody testing almost certainly UNDERESTIMATES exposure (which may be why it is so hard to get over 20% antibody positives in broad population studies)...

3/ The researchers wrote:

"This suggests that serological testing may significantly
underestimate past COVID-19 infections, particularly when applied to an asymptomatic population."

4/ In other words, if you test broadly and rapidly during an outbreak, you will find that a huge fraction of the population has been exposed/infected and is asymptomatic (we have seen this from PCR testing in settings like aircraft carriers, prisons, etc)...

5/ AND AS THE RESEARCHERS WROTE:

"These findings should also take into context the epidemiological dynamics seen during this COVID-19 wave. Japan took the atypical step of not instituting a mandatory lockdown..."

6/ "During this time, businesses, restaurants, and transportation were kept open, and public life continued relatively unabated. Nevertheless, the second wave peaked and subsided on its own... the possibility of herd immunity
should be considered." [con't]...

7/ "If this [herd immunity] were true, then the remarkably low mortality related to COVID-19 should also be
examined. Much like our cohort which had no reported hospitalizations, clinical severity in Tokyo was low [31 deaths, 14 million people]."

JFC. It was Earth all along.

Seriously, it is impossible to overstate the importance of this paper. It and the 40-cycle testing put all the pieces together.