There are a number of considerations that are relevant.
The first one is whether there is authority for this. I think there likely is.
With Mr. Barrett, I discussed a number of other issues, including the fact that this exceptional measure should be time-limited. That's an important consideration.
You mentioned religious or other rights that might explain why someone has not been vaccinated. That certainly needs to be one of the considerations. The “vaccine passport”—lets call it that—or proof of vaccination in ArriveCAN can probably be used as the rule. It should accommodate exceptions, particularly exceptions founded on the exercise of fundamental rights like freedom of religion. There need to be exceptions.
The last thing I would say is that the use of a measure like this—which again is exceptional and does impact civil rights—needs to be based on good science. There needs to be good evidence that vaccination actually protects people who would be in contact with a vaccinated person. It's entirely conceivable that such evidence exists, but we have not been shown it yet. That's another consideration.
I will leave it at that.