Will more states ban nonmedical exemptions for childhood vaccination?

While all 50 states allow exemptions for children who have a valid medical reason, and almost all states allow nonmedical exemptions for parents with either religious or philosophical objections, the political climate has recently shifted in favor of making exemptions more difficult to obtain.

In 2015, California, long known as a state with lenient provisions and high rates of opting out, followed the example of Mississippi and West Virginia and eliminated nonmedical exemptions. This move came in response to the widely publicized outbreak of measles in June 2015, traced to two Disneyland theme parks. That same year, at least twelve states considered bills on nonmedical exemptions.

Immunization rates in Mississippi and West Virginia show the benefits of strict exemption policies. In the 2014-15 school year, vaccinations in Mississippi for measles-mumps-rubella and diphtheria-tetanus-pertussis stood at over 99 percent for kindergarteners, the highest rate in the country. Only 17 children of kindergarten age received medical exemptions.

"Contrary to conventional wisdom, it may be politically feasible to limit exemptions to only medical reasons," writes Colgrove. "Health officials in both Mississippi and West Virginia report that overwhelming majorities of the public support their policies and that opposition comes from a very small number of the population. However, while sustaining policies is one thing, revoking a legal right that people have previously enjoyed presents a very different set of political circumstances."

Colgrove and his co-author, Abigail Lowin of Columbia Law School, suggest there are alternatives to eliminating nonmedical exemptions entirely. Many public health professionals are recommending retaining nonmedical exemptions but making them more difficult to obtain, requiring parents to receive educational counseling from a licensed health care provider, or to renew the exemption annually.