OLYMPIA, Wash. — Washington state lawmakers introduced a bill Friday that would ban personal exemptions for the measles, mumps and rubella (MMR) vaccine. 

The proposed legislation, sponsored by Rep. Paul Harris, R-Vancouver, comes in the midst of an ongoing measles outbreak in Western Washington, where the number of confirmed cases grew to 36 on Monday, according to the Washington Department of Health.

Public health officials scrambling to contain a measles outbreak in the U.S. Northwest warned people to vaccinate their children Monday and worried that it could take months to contain the highly contagious viral illness due to a lower-than-normal vaccination rate at the epicenter of the crisis.

Public health officials said that at least 30 of the people who contracted the disease were not immunized, and the majority of the measles cases affected children. 

Currently, vaccinations are required for Washington school-aged children, but state law allows parents to excuse their kids from some or all vaccines for personal, religious-related or medical reasons.

Clark County, Washington, has a vaccination rate of 78 percent, well below the level necessary to protect those with compromised immune systems or who can't get vaccinated because of medical issues or because they are too young.

Misinformation is circulating on social media, said Dr. Alan Melnick, Clark County public health director.

"What keeps me up at night is eventually having a child die from this completely preventable situation," he said. "It's still out there, even though it's been debunked, that the measles vaccine results in autism. That's nonsense."

House Bill 1638

Washington is one of 18 states that allows parents to refuse to vaccinate their children for reasons other than religious practice, according to a 50-state analysis of data tracked by the Immunization Action Coalition and the National Conference of State Legislatures. Non-medical exemptions have been granted to Washington residents since mandated immunizations began in the state in 1979. 

California, West Virginia and Mississippi's laws do not allow religious and philosophical exemptions in schools.

Interactive: Non-Medical Exemptions From School Immunization Requirements

Nearly five percent of Washington kindergarten students had exemptions in the 2017-2018 school year, according to a KING 5 analysis of Washington Department of Health data. Personal exemptions were the most common type.   

RELATED: Most Washington schools are failing to meet state's target for vaccinations 

Nearly 8 percent of the state's kindergarten students were labeled as out of compliance for not turning in paperwork to show proof of vaccinations or an exemption.

Interactive: Percent of Kindergarten Students Without Compete Immunizations 

State law requires local school officials to exclude out-of-compliance students – with the exception of students who are homeless – from class until they get their vaccines or produce a certificate of exemption. Currently, no state agency tracks whether or not the state's school districts are following through with this requirement.

Washington's exemption rate steadily crept upwards until 2010. At the time, Washington had one of the most lenient exemption policies in the nation, which allowed parents to simply submit the form without consulting a physician. Experts say it led to parents to choose an exemption for their child out of convenience or because of rumors they'd hear on a television talk shows.

Interactive: Washington's Kindergarten Students With Exemptions (By Type)

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