if you have to answer the question which of those two is the most powerful, it's the hygenic measuresa mask and stand six feet away from you and you wear a mask, i'm not going to catch a virus from you, you're not going to catch it to me. if i get a vaccine that's remarkably successful, if you ask searchers, what would they like from a vaccine, they would love a vaccine that's 75% effective, which means one out of four people that get it still may not be protected and it's probably not going to protect most people against mild disease or asymptomatic disease where you can still shed virus. so even if you've gotten a vaccine, you still need to wear a mask and i think that's going to be a very hard message to across to people. and if people just say, okay, great, i've gotten a vaccine, i can throw away masks and engage in high-risk activity, i think we're going to be right back where we started. >> yet we heard the president just this week mock joe biden for wearing a mask. here he is. >> did you ever see a man that likes a mask as much as him? and then he makes a speech and he always h