This is the only definitive study I've seen, and it recommends cotton masks: https://www.cambridge.org/core/services/aop-cambridge-core/c...

Probably the MacIntyre et al. paper. It's being misinterpreted everywhere in this very misleading fashion. See this blog MacIntyre wrote to clarify this: https://iser.med.unsw.edu.au/blog/impact-ppe-shortages-healt...

People misrepresenting this study are doing tremendous harm, it has to stop.

Thank you for sharing this updated clarification. I just shared it with that medical professional who showed me the original. Hoping to spread this clarification

There is also a study that shows many studies findings cannot be reproduced: https://en.wikipedia.org/wiki/Replication_crisis

From where I stand, the countries that have a culture of wearing masks are doing better with regards to coronavirus. At the very least, it seems like a good hypothesis.

I'm reminded of Naseem Taleb's statement that when you measure a table with a ruler, you are also measuring the ruler with the table.