Just guessing, but a person who has a medical condition that prevents them from being vaccinated (if there is such a thing) will be denied service. They’ll then be able to sue under the ADA’s provision that a reasonable modification needs to be offered due to their disability.
This would of course need to be someone with an actual verifiable medical condition identified by an actual doctor. Someone afraid of going down the slippery slope into authoritarianism wouldn’t stand a chance, nor would a guy so fat he can’t breathe in a mask, etc etc.
