> What does that have to do with Covid? The virus travels in saliva particles. > There is a huge body of evidence that viral load impacts severity There's ac

> What does that have to do with Covid? The virus travels in saliva particles. > There is a huge body of evidence that viral load impacts severity There's actually no evidence for this claim. It's a hypothesis, not a fact. It's essentially impossible to verify the initial viral load of an infectious dose without doing challenge trials, which we haven't done (yet). > There are actual real-world tests based on "average usage". We don't just have to make up our notion of efficiency based on your anecdotes. There are no real-world trials of n95 masks and Covid. There were a few studies pre-2020 with n95 masks in hospitals and influenza, SARS and MERS. Two hospital studies involved Covid. Essentially all of the research concerning masks and respiratory illnesses was summarized by the WHO here: https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(20)31142-9/fulltext https://www.thelancet.com/journals/lancet/article/PIIS0140-6... Figure 4 is the relevant figure. Any study with a 1 in the "respirator" column was conducted with an n95 mask. Overall, they're more effective than the non-respirator masks, but the confidence intervals for nearly all studies overlaps "no effect".