advisory director before to the cdc director. how confident are you that kids under 5 could get vaccinated, i don't know, before the end of march? >> i don't know. we'll know when we see the data. when we looked at the 5 to 11-year-old, there was really no difference in the immune response at the 10 microgram dose, given two doses three weeks apart in the 5, 6, 7, 8, 9, 10, 11. they all had the same immune response. apparently that's not true in the 5 and under group. it looks like it would be effective in the youngest child but not in the oldist child. we're all guessing. wool see whether or not this is going to be different doses for different ages or whether it's going to be more than two doses for different ages. time will tell. we'll see. right now we're sort of in an age of science by press release so it's a little confusing. >> dr. pernell and dr. offit, thank you. president biden promised there could be covid tests for everyone. that hasn't happened. why not?