SACRAMENTO, Calif. » California lawmakers are considering a measure that will require vaccinations for most children in public schools.

The state Senate was expected to take the final vote required before sending the contentious bill to Gov. Jerry Brown on Monday.

The bill strikes California’s personal belief exemption for immunizations, requiring nearly all public schoolchildren be vaccinated. While medical exemptions would still be granted to children with serious health issues, other unvaccinated children would need to be homeschooled.

Democratic Sens. Richard Pan of Sacramento and Ben Allen of Santa Monica introduced SB277 after an outbreak of measles at Disneyland in December infected over 100 people in the U.S. and Mexico.

If the bill becomes law, California would join Mississippi and West Virginia as the only states with such strict requirements.

Brown, a Democrat, has not said if he would sign the 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 Brown’s spokesman Evan Westrup.

The bill has seen heated opposition from parents who have come by the thousand to protest at the Capitol in recent weeks. Both legislative Republicans and some Democrats have come to their defense, asserting that the state is eliminating informed consent and trampling on parental rights.

Despite fervent pushback, the bill passed both the Senate and the Assembly with bipartisan support.

The Senate was expected to vote on changes made to the bill in the Assembly that make it easier to obtain medical exemptions. SB277 was amended to allow doctors to use a family’s medical history as an evaluating factor.

The authors also agreed to establish a grandfather clause, allowing students who currently claim a personal belief exemption to maintain it until their next vaccine checkpoint. Checkpoints occur in kindergarten and seventh grade.