@VGrubsky @taipan168 Local prevalence varies by orders of magnitude which is the primary determinant of deaths and dwarfs any particular individual's protective effect from a mask. Masks probably influence the former but in a complicated way and conflated with a large number of other factors.
@VGrubsky @taipan168 当地流行率按数量级变化，这是死亡的主要决定因素，使任何特定个体的口罩保护作用相形见绌。口罩可能会影响前者，但方式复杂，并与大量其他因素混为一谈。