this generally breaks down is general vaccine hesitancy then transmits into the pediatric hesitancy within communities as well, and that's something that we've got to continue to work on. >> doctor, thank you as always helping clear that up for us. appreciate it. wanting to switch gears, everybody, to the sports world. it's now official, though it leaked over the weekend on saturday afternoon by espn. tom brady now hanging up his football cleats. brady made the announcement on social media this morning ending days of speculation about his 22-year career. he said in part this. i have loved moy nfl career, and now it is time to focus ply time and energy on other things that require my attention. the legendary quarterback has won seven super bowl titles and three mvp awards throughout his 22 years in the nfl. nbc's morgan chesky joins me with more. this is huge, huge news. this broke saturday while i was on the air, espn reporting this