The difference is that in a standard trial, we are not intentionally infecting these older people.
In the control arm of a standard trial, some of the older patients will get infected, but they would have been infected any ways, and they will be treated with standard of care. So the ethical concerns here are substantially reduced. The older patients in the control arm are not facing any new risks, and in fact they might be getting better health care than they might otherwise receive.
In contrast, all the patients in a Challenge Trial are exposed more than they would have been exposed on their own. That introduces risk that they would not already have face.
Now, if there starts to be strong evidence accruing that the vaccine helps, then keeping older patients in the control arm (and not giving them the vaccine) raises a different ethical question. This, however, is an ethical challenge in most randomized-control clinical studies. Often there are rules put in place, or negotiated with regulators as the trial proceeds, where the trial can be brought to end more quickly if there is a strong positive signal, at which time the control arm will get the treatment too.
Yes, but dying from a virus is different than dying from the vaccine. Dying from the vaccine should be much less likely in this case, but we won’t know till we try.
Yes, I think that is what will be done.
I thought I already discussed them…