joining us now dean of the brown university school of public health dr. ashish jha and dr. dave campbelldly across the u.s. what are we to make of them and will the vaccines cover them? >> mika, good morning. this is a big race. so environment experts across -- viral experts are worried about the b 117 strain that is now spreading most rapidly in the state of florida where i am. it is very much a concern. we see if it doubles every 9 .1 days in florida. we see by late march, well into april, we will see that -- what's called the uk strain or the x 117 strain, the dominant strain in the united states. it's more transmissible. 35% to 45% more transmissible. so far the vaccinations are effective against this particular strain. the concern down in south africa, of course, is that that strain, the b1351 strain seems to be a bit more sneaky in its developing of mutations that avoid the impact of the vaccines that are currently available. mika? >> thank you, dave. excuse me. dr. jha, boy, this segment is going off the rails, isn't it? dr. jha, it's interesting, we see it around where we live. p