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Member Research & Reports

Member Research & Reports

GW: Analysis Finds California Law Led to an Increase in Childhood Vaccination Rates

A first of its kind analysis published by researchers at the George Washington University (GW) found that a 2016 California vaccine law boosted protective coverage against measles and other serious childhood diseases compared to states that acted as statistical controls. At the same time, the data also revealed a sharp increase in medical exemptions to the vaccine mandate, concentrated in a few California counties.

“The rise in medical exemptions strongly suggests parents who are reluctant to vaccinate their children are shopping for doctors,” said Dr. Avi Dor, professor of health policy and management at the George Washington University Milken Institute School of Public Health (Milken Institute SPH), principal investigator and the senior author of the study.

The study, which was published as a working paper by the National Bureau of Economic Research, analyzed the impact of the law that banned nonmedical or personal belief and religious exemptions to the vaccine mandate.

“People forget that measles was and still is a deadly disease, one that could surge again if we do not maintain high vaccination coverage,” said Dr. Dor. “State lawmakers who want to protect the public should take a hard look at lessons learned from California’s experience, and tighten educational and certification requirements so that medical exemptions are granted only when appropriate.”

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