well, i think at this moment, the key question for teenagers and younger children is whether or not vaccination of those groups has any direct benefit for them. and there's probably are a subgroup of children who have just slightly increased risk of severe disease. and definitely i think they should be included in vaccine programmes. but broader vaccination in childhood doesn't have so much direct benefit for them. so the real question is, will it prevent transmission and protect adults? and in a country like the uk, where the vast majority of adults are vaccinated, it's not such an important issue to vaccinate children in order to protect the adults and reduce transmission, because, first of all, children are not the major drivers of transmission. secondly, most adults are vaccinated. and then thirdly, we know the virus can still infect people who are vaccinated. so it doesn't fully prevent transmission, in order to do that. the biggest problem i see