The simple fact is that unmasked, the mean amount of time you can spend face to face with an infected person (with pre-Delta COVID) before you get infected your

The simple fact is that unmasked, the mean amount of time you can spend face to face with an infected person (with pre-Delta COVID) before you get infected yourself is maybe an hour or two. Many, many doctors and nurses were caring for COVID patients every day for 9 months before they were able to be vaccinated. Many spent hundreds-thousands of hours in contact with COVID patients and didn't get sick. This is extremely strong evidence that N95s work.