thing for prevention of transmission, especially to the vulnerable people who can't respond to the vaccines. >> picking up on the testing question, how often should somebody be testing, especially if you are vaccinated, maybe even boosted, and you feel fine? should you still be taking a test before you, for example, go see someone over the holidays? >> well, i recommend it. i think socializing over the holidays is something we can do this year more safely than last year because we have the vaccines and we have a better understanding of how the virus is transmilted. but you do use testing before gathering over the holidays. do it right before you go, not the morning of, not day before. that's the power of these rapid tests is it can give you an indication of am i contagious now. the other thing you can do is two days before and the day of, so yesterday, plus today, that's the best use and that's why you get two tests per kit. i would particularly recommend this if you're going to be visiting someone who's