There are many controlled studies on other respiratory disease like the flu, and some on other corona viruses like SARS the show high efficacy of masks. If you doubt the science, fall back on common sense. A respiratory barrier is going to have some value in diminishing the ability of a respiratory virus to spread.
The reason government and medical signaling on the subject has been so mixed is that it isn’t apparent they are very effective
The reason signaling has been mixed is because they were trying to preserve supply for medical professionals. The reason that medical professionals need them is because they work.
https://www.preprints.org/manuscript/202004.0203/v1
The reason government and medical signaling on the subject has been so mixed is that it isn’t apparent they are very effective
The reason signaling has been mixed is because they were trying to preserve supply for medical professionals. The reason that medical professionals need them is because they work.