dr. collins, abc news is reporting according to a leaked cdc report, the centers for dekreez control and prevention estimates more than 1 million people who received the moderna or pfizer vaccine have gone back for an unauthorized third booster shot. these are people walking into their pharmacies pretending its their first but it's really their third. there are any known safety concerns with people going out and getting a third shot right now? >> well, that's a good question, isn't it? i certainly wouldn't recommend that. in the absence of better data. you know, pfizer has run a trial on a third dose, and they have submitted that data and the fda is looking at it, but we don't know exactly what the safety issues might be. i suspect they won't be serious, but if right now the full immunization is good enough, i would not encourage people to jump the line and try to be out there and be ahead of what the recommendations are, if we don't need it and even if there's a small chance the third dose