A tool that reduces how much virus enters the air and reduces how much virus is breathed in is proven effective against a virus.
It's so difficult to predict physics. They ought to make some laws of physics to make predicting what will be effective easier.
nytimes.com/2022/11/10/health/

CleverLibre Social

CleverLibre Social is an inclusive social instance for open discussion, learning, and community.
All cultures welcome.
Hate speech and harassment strictly forbidden.