How long are you talking? I mean, nothing stops these people from going off and getting the vaccine themselves; what are you going to do, send mailers to them to never get a covid vaccine for the rest of their lives so that we can study them?
Just because something is not possible, does not make it any less required.
Yes, it does.
Because that would be like saying, just because all you got is a binocular with very limited magnification/resolving power, satelites for jupiter does not exist, because you cannot see them through it.
Someone should name this fallacy.