>> let's bring in one of the doctors you saw in that piece, my friend, dr. peter hotez. he's the co-director of the center for vaccine development at texas children's hospital and dean at by lor college of medicine. i want you to talk to my mom right now because she's watching the news every day and hearing about a new potential vaccine. what if we've already been vaccinated and boosted? now we need a different vaccine? for what? >> well, you know, right now, we don't know what's looming out there, but here's what we do know, stephanie, is that as long as we fail to vaccinate the world, mother nature is going to hurl new variants at us. she's not being coy here. she's telling us exactly what she has in mind. she gave us delta out of an unvaccinated population in india at the beginning of last year. she gave us omicron out of an unvaccinated population out of southern africa towards the end of last year. and yet another variant is clearly brewing out of