Isn't containing coughs and sneezes (along with hand washing, etc) one of the most fundemental parts of our understanding of how to prevent the spread of infectious diseases. The NHS has had the "catch it, bin it, kill it" motto for years as a way to prevent flu / common cold. There may not be studies specifically into covid-19 on this topic. But we do know that this is one of the primary spread vectors for basically every other similar respiritory disease. It's worth studying covid specifically just to be sure, but it would be bizarre if covid was different in this respect. And IMO it's completely wrong to say we have no evidence tht masks work.

> There may not be studies specifically into covid-19 on this topic.

There is only one study that looked at cloth masks and it was completed in 2015.

> And IMO it's completely wrong to say we have no evidence tht masks work.

I never said that. I'm saying that a high standard of evidence has not been met and there isn't much interest in running trials on cloth masks. The only one I could find is in Guinea-Bissau.

https://clinicaltrials.gov/ct2/show/NCT04471766

Here's some evidence for the proposition that masks mitigate droplet-based respiratory transmission to varying degrees: https://advances.sciencemag.org/content/early/2020/08/07/sci...

Both theory and empirical evidence. Mask wearing at least has the former: catching your own aerosols so you don't get other people sick so easily.

The best is remedies that have both. But don't think evidence without good theory is fine. I'm not sure it's even that much better than theory without good evidence.

That doesn't consider the possibly of a significant portion of the population infecting themselves. Remember, most people do not have the training to make a proper mask and use it correctly.

That's the reason we need randomized trials. How do masks work outside of the lab?

Also, it isn't accepted science that Covid-19 infects through aerosols.