 The idea is that by passing it through animal cells, these chicken cells, again and again, what you're doing is essentially you're weakening the effect of the virus on a human. It's still a virus, and it's still a virus that you can actually then take and put inside of a human. The thing is it's just not going to cause the same sort of disease that it would if it were really virulent and very strong. It's essentially weakened. This is called attenuation. You're kind of like...