State law addresses vaccinations.
Immunization Manual for Schools
This document addresses vaccinations for school-aged children
(1) The attendance of every child at every public and private school in the state and licensed day care center shall be conditioned upon the presentation before or on each child’s first day of attendance at a particular school or center, of proof of either (a) full immunization, (b) the initiation of and compliance with a schedule of immunization, as required by rules of the state board of health, or (c) a certificate of exemption as provided for in RCW 28A.210.090.
(1)Unless otherwise stated in this section, a child must be vaccinated against, or provide documentation of immunity against, each vaccine-preventable disease listed in WAC 246-105-030 at ages and intervals according to the national immunization guidelines in the " Advisory Committee on Immunization Practices (ACIP) Recommended Immunization Schedule for Children and Adolescents Aged 18 Years or Younger -- United States, 2019"; as published in the Morbidity and Mortality Weekly Report (MMWR) 2019; 68(5):112-114.