Masks work. "Our model quantitatively links mask efficacy to reductions in viral load & subsequent transmission risk. Our results reinforce that the use of masks by both a potential transmitter & exposed person substantially reduces the probability of successful transmission, even if masks only lower exposure viral load by ~50%. Slight increases in mask adherence/efficacy above current levels would reduce the effective reproductive number substantially below 1." #COVID19 https://www.nature.com/articles/s41598-021-91338-5