It's pretty fucking obvious that if you have Covid-19, and are expelling infected droplets into the air, almost any kind of mask will help reduce those droplets. I mean, wait for the double-blinded mask study (n=200) if you want. You may end up waiting for quite a while. Meanwhile, overall transmission rates in Asian mask-wearing countries are lower than Western transmission rates, despite taking many of the same precautions other than masks.

The point with masks, even rudimentary ones, is that they help prevent the wearer from transmitting respiratory disease.

And there's a point during a pandemic when you drop the Nature/Science level of evidence when you're talking about a relatively low-risk intervention like wearing a bandana.

In the words of the author of one the studies you disdain: "In normal times we'd say that if it wasn't shown statistically significant or the effective in real-world studies, we don't recommend it," he said. "But in the middle of a pandemic, we're desperate. The thinking is that even if it cuts down transmission a little bit, it's worth trying."

BTW, the author of the study I'm talking about here studied transmission of viral infections (influenza and coronaviruses) with an n of 111, not bacterial infections: https://www.nature.com/articles/s41591-020-0843-2 But there are multiple studies from the past decade that indicate that masks help prevent spread of respiratory viruses.

Finally, you harshly criticize my comment for lack of evidence, and yet you pull this one out: "It's likely that in members of the public the main route is touching an infected surface and then touching your eyes, nose or mouth." We have no idea if that's true or not at this point.

And here's another statement you pulled out of nowhere: "As soon as you drop any of those you're not just making the mask a bit less effective, you're probably increasing the risk over not wearing a mask at all."

You seem to have started from a position of defending the CDC, and then from there gone on cherry pick evidence or pull statements out of thin air.

There are people I know working at the CDC that I respect a great deal. But this PR campaign to lie to the American people to preserve mask stocks was a bad, bad idea.

> We know that qualified registered healthcare professionals who know the consequences of not wearing PPE correctly still struggle to do it all correctly.

No significant difference between fitted and non-fitted N-95 masks: https://www.ncbi.nlm.nih.gov/pubmed/21477136

And no, I wasn't even talking about wearing hospital-level PPE. I was talking about masks, and even mentioned bandanas, for crying out loud. But keep on spearing that red herring.

And here yet again, obviously N95 masks can help prevent transmission of respiratory viruses, including SARS-CoV-19. We know this to be true.

> This is not the CDC / WHO / etc lying, this is them talking about the science as they understand it.

You linked to some random ICU nurse, who makes some great points but has nothing to do with the CDC or WHO. But I agree that frontline health workers should absolutely have precedence to N-95 masks and other PPE.

> You're basing this on a small study carried out in a lab using research bacteria (not viruses) carried in a calibrated spray, that didn't include "people breathing through the mask".

Finally, you have no idea what I'm basing this on. Actually, it's common sense here that if you're infected, even as an asymptomatic carrier, wearing a bandana can reduce spread of droplets.