Leif Gram: Mr. Fix

Объясняет специалист

https://www.cnn.com/2021/05/19/health/masks-dr-wen-wellness/index.html
CNN: Are there circumstances where vaccinated people should still double-mask?
Wen: Again, this depends on you and your risk tolerance. Previously, the double-masking was because all the tools we had to prevent contracting Covid-19 were masks and distancing. Now we also have vaccines. For most routine settings like grocery stories, you could consider switching the N95 or KN95 for a normal surgical or cloth mask, and if you were double-masking, to switch to one mask.