There are those that argue even without a safer strain it is ethical under certain circumstances to still perform that sort of "challenge trial" though, where p

There are those that argue even without a safer strain it is ethical under certain circumstances to still perform that sort of "challenge trial" though, where people are deliberately exposed. A number of conditions would have to be met, such as all volunteer participation of course, very clear explanation and demonstration of understanding, no financial incentive, etc. But a faster vaccine could save many more lives than would be risked in the trial, and the risk itself could be very low, given the trial participants would be monitored closely and would get excellent medical care. Also obviously it would be restricted to young, healthy people without pre-existing conditions. To me it seems like a solid argument that given all those conditions (and possibly others I haven't thought of or mentioned), such a trial should be allowed. My understanding is that there are many people preemptively volunteering to participate.