[forgot_my_pwd]

It would be easy to issue certificates to people who have been vaccinated. Businesses already have guidelines for who can enter their premises, like wearing shirts in restaurants in spite of not wearing a shirt being legal.

[zenexer]

IANAL, but there’s no way that isn’t going to be contested. That’s not to say it can’t happen, but I have a hard time believing it could happen within a relevant timeframe.

The shirt and shoes rule is a health concern, much like what you’re describing here. Unlike vaccination certificates, though, it’s been around a lot longer and isn’t going to result in a heated political battle anytime soon.