The California Legislature has passed a bill that would require mandatory vaccinations for schoolchildren in the state, and the bill now awaits the signature of Gov. Jerry Brown.

The subject of protests and of heated debate in both the state Senate and the state Assembly, the bill - one of the toughest such measures in the U.S. - was introduced in February following an outbreak of measles at Disneyland that caused widespread infections.

The state Senate approved the bill in May, and the state Assembly has now passed it.

A spokesman for Brown, Evan Westrup, said 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." Brown has 12 days to decide whether to sign the bill.

If he vetoes it, it would need a two-thirds vote of the Legislature to override that veto, something that did not happen in the passage of the bill, which was by simple majority in both houses.

If he does sign it, children enrolling in either public or private schools or in day care would need proof of certain vaccinations, including those for measles or whooping cough.

Parents could no longer seek exemption from vaccination requirements for their children for religious and personal belief reasons, and if they decline to have their children vaccinated they would have to either have them home-schooled or enroll them in off-campus independent study programs.

Children with medical issues that might make vaccinations dangerous, such as those with compromised immune systems, would be exempt from the requirements but would need confirmation of their condition from a physician.

Large, vocal crowds of parents supporting both sides of the issue were on hand during a series of legislative hearings on the measure, which was supported mainly by Democrats in both the Senate and the Assembly.

Opponents said they considered vaccines unsafe or even dangerous, and charged the bill's sponsors with infringing on their right to choose whether or not to have their children vaccinated.

Sen. Richard Pan (D-Sacramento), a pediatrician and an author of the bill, refuted that. "The science remains unequivocal that vaccines are safe and vaccines save lives," he said during the Senate debate.

If the bill becomes law, it would make California the third state after Mississippi and West Virginia to eliminate religious and persona-belief exemptions.

The California bill includes a grandfather clause allowing students currently claiming a personal-belief exemption to retain it until their next vaccination checkpoint.

In California, those checkpoints are kindergarten and seventh grade.