California governor Gavin Newsom signed into law a new bill that would further restrict vaccine exemptions for children attending public schools.

Senate Bill 276 requires public health officials to review exemptions at any school found to have an immunization rate of less than 95%. The new law also mandates a public health review of any doctor who grants more than five medical exemptions in a calendar year. The state is now authorized to revoke any exemptions it deems fraudulent or medically inaccurate.

Children in California must be vaccinated in order to attend public or private schools, though the state permits exemptions if a physician identifies a medical reason for a child to skip some or all vaccines.