Thread: Masks and NPIs.

This thread reviews information published from Oct 2019 - Dec 2020.

The point is to see what was known/believed before & after discovery of COV2.

We'll start with research on epidemic/pandemic influenza (flu) from Oct of 2019.

Aerosols vs. droplets.
/1 pic.twitter.com/ee18xq0DTl

— Hold2 (@Hold2LLC) March 27, 2021