Chamatha: Challenge trials are like lazer printing, or three deep printing. A vaccine is come like the equivalent of that. You just take the jenome of the virus and, o boom, you've got the vaccine. And so i want to take a moment here and talk to chamoth about something, which is challenge trials. The united states is not doing these. I'm certain china is. Ah, do you think it's a moment in time where we need to think about the ethics and morality of challenge trials specifically? How do you execute them with that?...