and dr. leana wen. we've seen that pretty please hasn't worked, the honor system hasn't worked. in large part, the lotteries and the gift cards haven't worked. what do you think about this rule that's coming from the white house? >> i think it's definitely needed. we have to make getting vaccinated the easy choice and remaining unvaccinated the hard choice. so i think the biden administration is doing the right thing when it comes to compelling people to get vaccinated, requiring federal workers to be vaccinated, requiring contractors to be vaccinated and now saying that employees and the companies over 100 people should either be vaccinated or get tested. i think this is all going in the right direction, but i actually wish the biden administration would go even further, because planes and trains, for example, are also under their authority. a lot of people want to travel. i think it would make a big difference to say, if you want to travel, then you need to get vaccinated.