They're both possible dangers, even though you're trying to frame the Ebola example as a certain danger, which it just isn't, since there's a very decent chance that they won't infect anyone even without detention. It's not valid to label one as "reaction" and another as "proaction". They're both pre-crime measures for possible dangers. Neither of them is a certain danger.

It is also not "ineffective" in the hypothetical I was discussing. You seem to insist on the point that I wish to hoist forced vaccinations for COVID, which I don't. I'm strictly speaking in the abstract given a hypothetical where there's a vaccine capable of preventing transmission of a disease that is much more deadly than COVID.

But I agree with your main point that the circumstances should be very extreme before such measures are considered. If there's a contagious disease that is killing 10-50 percent of infected people and early quarantine measures have failed and we have a vaccine that seems effective at preventing transmission, then I'm probably in support of forced vaccinations, although I suspect it might not be necessary since everyone will be desperate to get it.