getting the full adult 30 microgram pfizer dose. for kids 5 to 11 it will be 10 micrograms. can you explain why are the doses based on age not weight considering, you know, a 12-year-old could be smaller than an 11-year-old. >> what we do know is that pfizer actually tested a few different doses before they settled on the 10 microgram dose used in the phase three trial. so what i conjecture is that the 10 microgram dose is what seemed to do the best in that age group. >> what would you advise parents do if their kid just turned 12, go with the 12 to 18? >> yes, definitely go with the 12 to 18 full 30 microgram dose of the vaccine. >> you heard in nick's piece, several schools are considering pulling back on their mask mandates, but community transmission is still considered high in almost 80% of counties in the u.s. does this worry you considering