Parents can opt out of vaccinations for their children by citing religious or philosophical reasons....easy form to fill out and it gets them off your back.
Not sure if this is a state or federally-run opt-out program.
It is state run and rules vary state to state.
In most states its an all or nothing opt-out. You can’t get some shots and then claim religous exemption because you don’t want others, like the chicken pox vaccine.