We KNOW how well masks affect transmission in the population. We don’t need theories or lab experiments. California has provided us with a 40 million population, real-life experiment: Does mandating masks affect the spread of Chinavirus?
With the second highest rate of compliance and with 2 months of experience, we can look and see: No, it does not. It has no measurable impact. At all.
Since the incubation period is under a week for the majority, and under 2 weeks for almost everyone, if masks reduced transmission we would see a significant (measurable) reduction in the spread within 2 weeks tops. And it didn’t happen.
Sorry.
Masks plus the other public health measures, including social distancing, are helping Hong Kong get through a serious wave.
California is behind the bar as the rules weren’t followed there.
Look at countries that already experienced this and won against the wuflu with masks - such as Taiwan, Thailand, Vietnam, Slovakia, Poland, Greece, etc. etc. etc.