Takeaways
- Full repeal of nonmedical exemptions was associated with a 2–4 percentage point increase in kindergarten vaccination rates for DTaP, hepatitis B, MMR, and polio within three years.
- Exemption rates declined significantly, driven by reductions in nonmedical exemptions, with minimal substitution toward medical exemptions (increase of only 0.4 percentage points).
- Partial repeals generated smaller and less durable impacts, indicating that comprehensive exemption removal is more effective for maintaining vaccination coverage amid rising vaccine hesitancy.
Childhood vaccination rates in the United States have declined in recent years, raising concern about increasing vulnerability to vaccine-preventable diseases and the role of exemption policies in this trend. A cross-sectional study published in JAMA Pediatrics examined how the repeal of nonmedical vaccine exemptions in select states was associated with kindergarten vaccination rates from 2011 to 2023.1,2
Study purpose and design
The study sought to evaluate whether eliminating nonmedical exemptions—such as personal, philosophical, or religious exemptions—was associated with higher vaccination coverage among kindergartners. Investigators used annual state-level data reported to the Centers for Disease Control and Prevention (CDC), including vaccination rates for diphtheria-tetanus-acellular pertussis (DTaP), hepatitis B, measles-mumps-rubella (MMR), and poliovirus vaccines, along with medical and nonmedical exemption rates.
A staggered difference-in-differences approach compared 4 states that fully repealed nonmedical exemptions—California (2015), New York (2019), Maine (2019), and Connecticut (2021)—with states that maintained their exemption policies. Vermont and Washington, which enacted partial repeals, were analyzed separately. These policy changes were examined using event-study models to identify changes up to 4 years after repeal.
Key findings
Across states that enacted full repeal, exemption rates declined substantially. According to the study, “total exemptions declined by 3.2 (95% CI, 1.9-4.4) percentage points within 3 years of repeal,” and this change “primarily reflected reductions in nonmedical exemptions, which fell by 3.6 (95% CI, 2.0-5.1) percentage points.” Minimal substitution toward medical exemptions occurred, with a small increase of “0.4 (95% CI, 0.04-0.7) percentage points.”
These reductions occurred without detectable differences in prerepeal trends. The authors noted “no evidence of differential trends before repeal,” supporting the validity of the observed associations.
Vaccination coverage increased in states that repealed nonmedical exemptions. Three years after repeal, DTaP vaccination rose by 4.1 percentage points (95% CI, 3.3-4.9), hepatitis B by 2.8 percentage points (95% CI, 2.1-3.5), MMR by 4.0 percentage points (95% CI, 3.1-4.9), and polio by 3.8 percentage points (95% CI, 2.9-4.6). These increases were consistent across estimation models and robust to sensitivity analyses.
The authors observed that “the impact of total exemption repeal grows over time,” with the largest increases occurring 3 to 4 years after policy implementation. This pattern may reflect lagged enforcement periods or phased implementation.
Partial repeals and differing policy effects
States with partial repeal—Vermont and Washington—had more modest changes. Total exemptions fell by 2.2 percentage points (95% CI, 1.4-3.0), and vaccination increases were smaller and less persistent than those seen in full-repeal states. In Washington, which repealed nonmedical exemptions only for MMR, the study reported a “short-term boost to vaccination rates, with some decline by year 4.”
Discussion and implications for practice
The findings indicate that comprehensive repeal of nonmedical exemptions may be an effective strategy for increasing kindergarten vaccination rates and countering trends of declining coverage. The study highlights that “restricting exemptions may play a role in maintaining vaccination coverage” during a period of increasing vaccine hesitancy. Minimal increases in medical exemptions suggest limited circumvention of new requirements.
The authors emphasized that wide-ranging repeals produced the most sustained improvements: “states that passed more wide-ranging repeals experienced greater relative increases in vaccination coverage.”
Conclusion
The authors note several limitations, including reliance on state-level aggregated data, inability to measure demographic disparities, and potential unobserved behaviors such as shifts toward homeschooling. The study period ended in 2023, which may not capture more recent changes in vaccination attitudes or policies.
State repeal of nonmedical vaccine exemptions was associated with meaningful increases in kindergarten vaccination rates, ranging from 2 to 4 percentage points, and substantial reductions in exemption rates. The study concludes that comprehensive repeal policies “played a role in maintaining vaccination coverage amid growing vaccine hesitancy,” offering evidence to inform state-level immunization policy decisions.
References
- Bald A, Gold S, Yang YT. State Repeal of Nonmedical Vaccine Exemptions and Kindergarten Vaccination Rates. JAMA Pediatrics. Published online October 27, 2025. doi:https://doi.org/10.1001/jamapediatrics.2025.4185
- Gambrell A, Sundaram M, Bednarczyk RA. Estimating the number of US children susceptible to measles resulting from COVID-19-related vaccination coverage declines. Vaccine. 2022;40(32):4574-4579. doi:10.1016/j.vaccine.2022.06.033
