hopefully that changes soon. elizabeth cohen, thanks. let's discuss with an expert. cnn medical analyst, dr. leana wen, the author of "lifelines." dr. wen, merry christmas eve. grateful you could share part of it with us. the u.s. government didn't purchase enough of this covid-19 prevention drug for the 7 million americans eligible to take it. would you say that was a mistake by the biden administration? >> boris, hindsight is always 2020. in retrospect, the biden administration should have purchased more but they had to make a bet and say, is this going to pan out and i'm really happy that it looks like this particular treatment works. just to emphasize what this is, this is an antibody infusion. so people who are immunocompromised their bodies are not able to mount a substantial response to the vaccine which is the reason they