Legislative efforts to allow more parents to exempt their children from vaccinations required by public schools have largely failed, according to a research letter published today in The Journal of the American Medical Association (JAMA).

From 2009 to 2012, there were 36 attempts in 18 states to change immunization requirements. Of those, 31 were intended to expand the scope of exemptions, typically for personal or religious reasons.

But none of the bills to expand exemptions passed, though three of five bills to restrict exemptions made it into law. Those bills were passed in California, Vermont, and Washington.

Mississippi, West Virginia, and New Jersey led the U.S. with a combined total of 16 attempts to allow for more personal belief exemptions—those not tied to medical or religious beliefs—but none of them passed.

“Exemptions to school immunization requirements continue to be an issue for discussion and debate in many state legislatures,” the letter's authors wrote.

Widespread vaccination helps protect those who can’t be vaccinated, such as infants and people with compromised immune systems. This phenomenon is known as “herd immunity.” Vaccine requirements are supported by major disease prevention groups, such as the U.S. Centers for Disease Control and Prevention (CDC) and the World Health Organization.

It should be noted that one of the authors of the research letter, Dr. Alan Hinman, program director at the Center for Vaccine Equity at the Task Force for Global Health, has received grants from the CDC, Novartis Vaccines, and the Merck Company Foundation.

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Vaccine Exemptions Spur a Rise in Preventable Diseases

A 2006 study in JAMA found that states with greater numbers of personal belief exemptions—and broad exemption laws—saw an increased incidence of whooping cough.

Clusters of children whose parents requested non-medical exemptions were responsible for a 2010 whooping cough outbreak in California—the worst in 50 years—according to research released last year. In San Diego County alone, there were 5,100 exemptions and 980 whooping cough cases. Overall, the outbreak caused 9,120 instances of the disease and 10 deaths.  

So far this year, one infant—one too young to be vaccinated—has died in California due to whooping cough.

California was one of three states who passed bills restricting personal belief exemptions, making the exemptions harder to obtain.

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Why Do Parents Ask for Vaccine Exemptions?

The parents of many the children involved in the 2010 outbreak cited religious beliefs as the reason for their exemptions.

In 2012, California lawmakers restricted the reasons parents could offer for not vaccinating their children. Effective Jan. 1, 2014, parents, guardians, and emancipated minors in California must now have a doctor's signature in order to get this exemption, according to the National Vaccine Information Center.

States that allowed parents to claim "philosophical" exemptions had 2.54 times more non-medical exemptions than states that didn’t, according to a 2012 study in The New England Journal of Medicine.

According to a 2005 study published in the journal , the parental decision not to vaccinate was “significantly associated with beliefs in the safety and utility of vaccines.”

Researchers involved in that study said parents need to be better educated about the safety and effectiveness of vaccines.

You can view the current vaccination schedule for school-aged children on the .

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