As of 2011, all 50 states have enacted vaccine laws that require proof children have received certain vaccines in order to attend daycare, middle school, high school and college.
However, in most states citizens currently have the legal right to opt out of using vaccines.
All 50 states allow a medical exemption to vaccination (medical exemptions must be approved by an M.D. or D.O.); 48 states allow a religious exemption to vaccination; and 18 states allow a personal, philosophical or conscientious belief exemption to vaccination.