other thing we have to think, about as a challenge, of actually getting the vaccines distributed to low and middle income countries, is that we're doing everything we can for. that right now they're nine billion doses, it would be really difficult to get them all into. arms we need to push that part really hard. to >> so on the question of, the data about people coming for booster shots, exceeding those getting initial doses is so striking to, me because i do think, it's an example of the kind of, the challenge we face, which is the further we go, the more people that get their first shot, every day, the more the people not getting the shot shrinks in showings to a group that really doesn't want to, and we're now in that, we're getting closer to that group, and questions about how to reach that, group and whether we can get enough of them to get something that looks like heard immunity, is really the open question, i wonder if you think we have an answer to.