Mo. Rev. Stat. § 197.168

Each year between October first and March first and in accordance with the latest recommendations of the Advisory Committee on Immunization Practices of the Centers for Disease Control and Prevention, each hospital licensed under this chapter shall offer, prior to discharge and with the approval of the attending physician or other practitioner authorized to order vaccinations or as authorized by physician-approved hospital policies or protocols for influenza vaccinations pursuant to state hospital regulations, immunizations against influenza virus to all inpatients sixty-five years of age and older unless contraindicated for such patient and contingent upon the availability of the vaccine.