Ok new news again: which do you think is riskiest/riskier/less risky:

1) take a bus with open windows for an hour [I thought this Riskier]
2) sit and eat in an enclosed space at a table for 10, indoors, no windows, 15-30 mn [I thought this Riskiest]
3) participate in a buddhist retreat for a full day, outdoors, with hundreds of others? [I had thought this least risky]

Well there are data! From mid-January in China where the same group from Wuhan did all those things. Video here but in French. But great graphics, worth looking at.

Turned out the worst, and by far, was the bus. One person on one bus infected almost everybody else on that bus, except most of those sitting right at the open windows.

Being at a table, even indoors and unventilated for 15-30 mn, infected few if any, same for being outdoors with people.

Excellent within-group research.

Also, no masks. One mask on that one person could have prevented *all* the infections.