Here is a reason why to use a close fitting N95 or similar mask in higher risk areas, and to get the new booster. My nephew is a postmaster and got covid on Sunday, 3 days ago; he started Paxlovid on Monday and feels much better so is planning on going to work tomorrow (some people believe 5 days in itself is enough, one doesn't need to test to see if they are negative). He was last vaccinated in October. Masks that cover your nose and mouth and form a good seal around you face work by decreasing the amount of virus/bacteria/pollen that you inhale. An N95 mask removes at least 95% of 1 micron and larger particles (smaller particles in aerosols[snot] are larger). Even if some virus gets through, the viral load is decreased so your immune system isn't as easily overloaded. If you are immunocompromised a P100 mask/respirator blocks almost 100%. Masks also help by keeping your hands away from your face. Part of my PhD was on fluid and gas flow through porous and permeable media. The mask/no mask mess during the pandemic was a cluster of (1) not enough data yet on the virus or (2) mask availability and efficiency, (3) bureaucrats and politicians mangling scientists' recommendations and initial research, and (4) other infrastructure/committee messes.