I’m not sure there was any popular doubt over the efficacy of N95 masks. The problem was rather getting one - marketplaces like Amazon restricted access to masks if you weren’t affiliated with a hospital. So you were left with sketchy deals and weird vendor sites.
I suspect Amazon killed quite a few people over the last year by restricting access - supply scaled pretty quickly.
I suspect Amazon killed quite a few people over the last year by restricting access - supply scaled pretty quickly.