California passed a new law in 2016 requiring vaccines to attend school, the only exemption is a valid medical reason, removing all other exemptions.
The courts have sided with the state so far, and its unlikely at this point the law will be overturned as its unlikely the California Supreme Court would hear the challenges and let the lower court rulings stand.
The challenges in federal court went nowhere as well. California, Mississippi and West Virginia have removed religious and personal exemptions.
https://www.courthousenews.com/california-appeals-court-upholds-vaccination-law/