Strict school vaccine mandates work, and parents don’t game the system − new research

(The Conversation is an independent and nonprofit source of news, analysis and commentary from academic experts.)

Y. Tony Yang, George Washington University; Anthony Bald, California State University, Fullerton , and Samantha Gold, Cornell University

(THE CONVERSATION) When four states between 2015 and 2021 stopped allowing parents to opt their children out of receiving routine vaccines without a medical reason, vaccination rates among kindergartners increased substantially. That’s the key finding from our new study published in the medical journal JAMA Pediatrics.

All states require children entering kindergarten to be vaccinated against infectious diseases like measles and polio. Parents can request medical exemptions if, for example, their child has a severe allergy to a vaccine ingredient. But most states also allow nonmedical exemptions based on religious or philosophical beliefs. To examine whether state policy on vaccine exemptions could counter falling vaccination rates, we probed data from approximately 2.8 million kindergartners across multiple states from 2011 to 2023.

California, New York, Maine and Connecticut completely eliminated nonmedical exemptions during this period. In those states, exemption rates fell by 3.2 percentage points on average within three years...