I think vax proof is a given at this point. I think we will see it manifest, at a minimum, anywhere that people are expected to remain indoors, in close proximity to the same group of people. (At work, e.g., as the mayor suggested today.) I said this a while back but I think the way out of vaccine reluctance is to make it as inconvenient as humanly possible not to be vaccinated. And as we head toward an election year where looking foolish is not going to be a good look, I think we will see more and more idiot Republicans wander over, as some of them have been doing both in Congress and in the states. When the governor of Alabama goes off on anti-vaxxers, you know something is moving.