protection. i don't think the question is if we're going to get a booster shot. the question is going to be when. so, to be frank, i'm actually excited that the scientists can sit down, look at all these studies, and make a decision as to when majority america will need that third shot. >> so as we wait for that, you just mentioned t cells. there is a study from swedish researchers that came out yesterday, and half of the people that they looked at had preexisting immunity to the coronavirus, but they had never contracted it. this had to do, as i understand it, with their t cells. my question on that is any sense of how many people may have that preexisting immunity, and how effective is that versus being fully vaccinated? >> yeah, so i think that is also going to be a really big question that scientists need to look at. i've been excited about this whole t cells and b cells, you know, six, seven months ago, even before the vaccine rollout. and the reason for that is, like you just mentioned, there are