Gov. Jerry Brown signaled that he was open to such a bill. “The governor believes that vaccinations are profoundly important and a major public health benefit and any bill that reaches his desk will be closely considered,” said Evan Westrup, a spokesman for Brown.

The legislation does not address children who are completely home-schooled. It would still allow children to avoid vaccination for medical reasons including allergic responses and weak immune systems. The mandate only applies to children attending public or private schools.

Currently, 13,592 children have personal belief affidavits on file; of those, 2,764 were identified as based on religious beliefs. Pan said if the bill passes, the religious exemption would also disappear but he is open to a separate conversation on that issue.