Putting aside the knee-jerk response of "of course a mask that covers your disease holes is protection against giving other people your disease"... https://www

Putting aside the knee-jerk response of "of course a mask that covers your disease holes is protection against giving other people your disease"... https://www.sciencedirect.com/science/article/pii/S1201971216310104 https://www.sciencedirect.com/science/article/pii/S120197121... (2016) on the role of (incidental) face coverings to prevent population-level disease at large gatherings. https://www.sciencedaily.com/releases/2019/09/190903134732.htm https://www.sciencedaily.com/releases/2019/09/190903134732.h... (2019) on the role of personal protective equipment on stopping contraction of respiratory disease (flu). And to top it off: https://academic.oup.com/cid/article/65/11/1934/4068747 https://academic.oup.com/cid/article/65/11/1934/4068747 (2017) meta-analysis, including a controlled section on effectiveness on population face mask use to prevent the spread of SARS-CoV. We had the evidence.