[user104658]

Not really. If you know that YOU have Covid and need to go out and about, you should really wear one as a courtesy. At this point we know it doesn't stop transmission entirely and they don't do much at all to stop you getting it (N95's actually DO help though), but they do reduce your chances of infecting others if you're actively coughing/sneezing. Of course the best answer is still just to stay at home if you're ill.