From 2009-2012, 36 bills introduced in 18 states sought to modify school immunization mandates, with the majority seeking to expand exemptions although none of the bills passed, according to a study in JAMA.

"School immunization mandates, implemented through state-level legislation, have played an important role in maintaining high immunization coverage in the United States," according to background information in the article. Immunization mandates permit exemptions that vary from state to state in terms of type of exemption (e.g., religious, personal belief, medical). Certain types of exemptions (especially personal belief exemptions) and the ease of obtaining them can help predict the increased disease risk among exemptors themselves and in the communities in which they reside.

Saad B. Omer, M.B.B.S., M.P.H., Ph.D., of Emory University, Atlanta, and colleagues analyzed legislation proposed from 2009 through 2012 at the state level to modify exemptions to school immunization requirements. The bills were classified into those that did or did not have a personal belief exemption (PBE). In addition, the researchers listed administrative requirements included in each bill, defined as one that would require action from the child's parent or guardian beyond merely signing an exemption form. Bills were also classified as expanding or restricting exemptions.

Eighteen states introduced 1 or more exemption-related bills. Among 36 bills introduced, 15 contained no administrative requirements, 7 had 1 or 2 administrative requirements, and the remaining 14 contained between 3 and 5 administrative requirements.

Of 20 states with a current PBE, 5 saw a bill introduced to restrict exemptions and 1 saw a bill introduced to expand exemptions. Among the 30 states without a PBE, none saw a bill introduced to restrict exemptions and 13 saw a bill introduced to expand exemptions. Of the 36 bills introduced, 5 were categorized as restricting exemptions and 31 as expanding exemptions. None of the bills categorized as expanding exemptions were passed. Three of the 5 bills categorized as restricting exemptions were passed (Washington, California, and Vermont).

"Exemptions to school immunization requirements continue to be an issue for discussion and debate in many state legislatures," the authors write.