lohse?that give you pause, this idea that she's saying segment's the population won be so effective? >> i think you have to be careful when you do it. but the young people will not carry the virus for a long time. and once they've gone through the infection they won't infect any of the elderly anymore. so yes, there will have to be and you have to differentiate regionally, there will have to be a transient phase when you really have to protect the elderly people from the young people, which is what we're doing now anyway. once the young people have gone through the infection, they could safely care for the elderly. >> natalie, what do you think? >> but there's a big interim period which i don't quite understand how that works. i mean, we have young people work in nursing homes. we have young people that live with older parents. i just don't think it's very realistic to think about segmenting the population. i really feel like the best way to protect everyone is to include protecting young pe