or two months after the johnson & johnson single dose vaccine. how significant is this as we wait to hear how severe cases may be because of the new variant? >> this is the clearest language we've had. there's been a lot of back and forth. the change now is they were saying that people over the age of 50 should get a booster. people under 50 could or may get a booster they said before. now they're saying all adults should get a booster. and i think that's an important message because i think the thing that we think about with vaccine escape immunity, this idea that the variant is somehow escaping the immunity of the vaccine, it's more like you have a cushion effect. right now there's a significant cushion effect of these vaccines against the circulating virus. with this new one, there may be less of a cushion. less of a sort of buffer effect there. if you have a booster, you'll increase the buffer, if that makes sense. more of a cushion and when we're dealing with something that's unknown, we're still trying to