immunization, i think it's going to give really robust protection. that might be it for a while. we may not need annual boosters. this could be the third and done. >> let's hope that is the case. dr. reiner, while some americans are eager to get a third shot, millions of americans still haven't gotten their first shots. so are you concerned that this could make the vaccine hesitant even more hesitant? >> well, it shouldn't. i think the messaging from the cdc should be that we have excellent data showing that a third shot of particularly the mrna vaccines produce really a very robust immune response. and as my old friend and colleague dr. hotez said, it's also possible that this third dose will actually create a much will longer-lasting immunity. so i think this should be both reassuring and should underscore the need for folks in this country who have not been vaccinated to start the process now. get your first shot now.