All phases will be testing for safety to varying degrees. So... a challenge trial at phase III will still have risks. Right now, I don’t think we have any vacc

All phases will be testing for safety to varying degrees. So... a challenge trial at phase III will still have risks. Right now, I don’t think we have any vaccines ready to enter phase III? COVID19 does seem to be actively spreading in the population currently. So I don’t think there would be an issue finding participants for a phase III trial. At the point that we’re ready for phase III trials. If there is no population where COVID19 is actively spreading, perhaps challenge trials could be considered?