California Code, Health and Safety Code - HSC § 120455

(a) Notwithstanding any other law, a person shall not be liable for any injury caused by an act or omission in prescribing, dispensing, ordering, furnishing, or in the administration of a vaccine or other immunizing agent, including the residual effects of the vaccine or immunizing agent, if the immunization is required by state law, administered in accordance with guidance from the State Department of Public Health pursuant to Section 120164, or given as part of an outreach program pursuant to Sections 120400 through 120415, inclusive, and the act or omission does not constitute willful misconduct or gross negligence.

(b) This section shall remain in effect only until January 1, 2030, and as of that date is repealed.