That's for an individual. If everyone wore *VERY BAD* masks, I guess the number of deaths would drop by a yuuuge factor, maybe 90%. Why? p is probability of infection, look at 1-p^n because everyone is reducing.— Nassim Nicholas Taleb (@nntaleb) April 12, 2020
For 2 pple masks act a 2-way filter, 1-p^2. Yuuge.