Okla. Stat. tit. 10, § 413

Any minor child, through his or her parent or guardian, may submit to the health authority charged with the enforcement of the immunization laws, a certificate of a licensed physician stating that the physical condition of the child is such that immunization would endanger the life or health of the child; or upon receipt of a written statement by the parent or guardian objecting to such immunizations because of religious or other reasons, then such child shall be exempt from the provisions of this act.