Religious Vaccine Exemptions in Kindergartners: 2011-2018.

BACKGROUND: Forty-five states permit religious exemptions to school immunization laws; 15 allow personal belief exemptions. Updated religious exemption estimates are lacking, and it is unclear if personal belief exemption availability impacts religious exemption rates. We aimed to (1) update religious exemption trends in kindergartners, (2) compare states' proportions of kindergartners with religious exemptions by personal belief exemption availability, and (3) describe whether the proportion of kindergartners with religious exemptions changed in Vermont after it eliminated personal belief exemptions in 2016.

METHODS: We analyzed Centers for Disease Control and Prevention data on exemptions for children entering kindergarten from 2011 to 2018, including 295 state-years in our final analysis. Using a quasi-binomial regression analysis, we compared mean proportions of kindergartners with religious exemptions in states allowing both nonmedical exemptions against states with religious exemptions only, adjusting for policy strength and school year.

RESULTS: States with religious and personal belief exemptions were one-fourth as likely to have kindergartners with religious exemptions as states with religious exemptions only (risk ratio 0.25; 95% confidence interval 0.16-0.38). After Vermont's policy change, the mean proportion of kindergartners with a religious exemption increased from 0.5% to 3.7%. States were significantly more likely to have kindergartners with religious exemptions during the 2017-2018 school year compared with the 2011-2012 school year ( P = .04).

CONCLUSIONS: Religious exemption rates appear to be associated with personal belief exemption availability, may be subject to a replacement effect on personal belief exemption elimination, and are increasing. Researchers and policy makers should confirm findings with individual-level studies and reconsider the purpose and nature of religious exemption laws.