@sneak why would it be otherwise? hospitals around the country (US) are making and enforcing their own employment policies wrt the COVID vaccines. there doesn't need to be a law.
@black6 hospitals have to be built to fire code (for public safety). that's a law. hospitals can't overcrowd with people (for public safety). that's a law. hospitals can't sell heroin to all comers without a license (for public safety). that's a law.
i don't think your position is consistent with what people mean when they say "a hospital" in 2021 in the united states, which implies a lot of existing laws and regulations about a building open to the public.