California lawmakers moved ahead Wednesday with tougher rules that limit parents from choosing whether to vaccinate their children. The California proposal would give state public health officials instead of local doctors the authority to decide which children can skip their shots before attending school.

Senators sent the measure to the Assembly as the nation struggles to stem the highest number of measles cases in decades and as state efforts to strengthen vaccine requirements draw emotional opposition.

This year has seen substantially more measles cases than 2018, according to a Centers for Disease Control and Prevention report released in April. By the end of March, the number of confirmed cases nationwide had exceeded the 372 reported last year. As of May 17, half a dozen states have faced measles outbreaks amounting to 880 total cases.

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California has been particularly impacted, with multiple measles outbreaks being reported so far this year. Earlier this month, moviegoers were potentially exposed to the measles during a screening of "Avengers: Endgame" in Orange County. In April, more than 900 students were quarantined across two colleges.

Democratic state Sen. Richard Pan of Sacramento said his proposal is needed because some "unscrupulous physicians" have been selling medical immunization exemptions since California ended non-medical exemptions in 2016. The bill was signed into law following a measles outbreak at Disneyland. The CDC reports that 125 cases were connected to that outbreak.

Under the new proposal, doctors would have to certify that they examined the patient and then send the state health department the reason they are recommending the exemption. State and county health officials also could revoke exemptions if they are found to be fraudulent or don't meet federal immunization standards.

"This is about keeping our community safe," Pan said.

He said exemptions would still be allowed for the less than 1% of students who should avoid vaccinations because they have a severe allergic reaction or impaired immunity from a liver problem, the HIV virus, chemotherapy or other conditions.

The measure passed on a party-line 24-10 vote, with no Republican support. Four Democratic lawmakers did not vote, with two Democratic senators saying it goes too far or reneges on lawmakers' earlier promise not to infringe on medical exemptions.

Several Republican lawmakers said they agree the state should crack down on doctors who sell medical exemptions but that they should be sanctioned by the state medical board through the normal disciplinary process.

"Why isn't the medical board dealing with these bad actors?" Sen. Jeff Stone said.

The Republican from Temecula called Pan's bill "a dangerous intrusion, not only into the doctor-patient relationship but also the personal liberties of the parents and their children."