Masks work. I’d say they are the single most important line of defense against COVID at present. #WearAMask

@DrEricDing has compiled a great evidence review in this thread. https://twitter.com/drericding/status/1317694942479876097

If you are with people indoors, and everyone is wearing a mask, the protection is much better. This is how many hospitals have managed to contain transmission of COVID.

You dont need to wear a mask at home when you are around people you normally live with, unless someone is ill

If you are outdoors, alone or with your own family, you don’t need a mask.

Non-medical masks work. @jeremyphoward outlined the data in this great thread in June. https://twitter.com/jeremyphoward/status/1274036544387477504