No school nurse employed by a local school board, person employed by a local health department who is assigned to the public school pursuant to an agreement between the local health department and the school board, or other person employed by or contracted with a local school board to deliver health-related services shall be prosecuted under Chapter 11 (§ 4.1-1100 et seq.) of Title 4.1 or § 18.2-248, 18.2-248.1, 18.2-250, or 18.2-255 for the possession or distribution of cannabis oil for storing, dispensing, or administering cannabis oil, in accordance with a policy adopted by the local school board, to a student who has been issued a valid written certification for the use of cannabis oil in accordance with § 4.1-1601.