and it's important that we look across the whole to make sure transplants are successful when available. >> these policies are put in place to best prepare patients to have successful transplants. doctor, i want you to help us understand, how should we read these new pfizer trials, clinical trials for a new omicron variant vaccine. let's say they come out with the vaccine a few months from now. why do we need a specific one for this variant, and what does that mean if we have been vaccinated and have the booster, how does this vaccine help? >> the most important thing to take away is this is incredible good news. when we think about the two years it took us to be able to generate this robust vaccine that's available and around for everyone to take against covid, the ability of our vaccine companies, like pfizer, to now produce very quickly a variant-specific vaccine speaks to the amazing advances in the technology. >> but do we need to take it. >> well, we will see.