I think a certain amount of time after it has been available to everyone is the fairest route. Tracking who has taken it is a train wreck. For the sake of argument, lets say it is finally available to everyone in March (I assume high risk will have already had the option to take it before this), by June, you should have no restrictions at all. If you are still scared of the virus months later, then you can shelter away or decide to take the vaccine. If you don't take the vaccine, that's your problem, not society's.