The 2016 California policy to eliminate nonmedical vaccine exemptions and changes in vaccine coverage: An empirical policy analysis

Abstract

BackgroundVaccine hesitancy, the reluctance or refusal to receive vaccination, is a growing public health problem in the United States and globally. State policies that eliminate nonmedical (“personal belief”) exemptions to childhood vaccination requirements are controversial, and their effectiveness to improve vaccination coverage remains unclear given limited rigorous policy analysis. In 2016, a California policy (Senate Bill 277) eliminated nonmedical exemptions from school entry requirements. The objective of this study was to estimate the association between California’s 2016 policy and changes in vaccine coverage.Methods and findingsWe used a quasi-experimental state-level synthetic control analysis and a county-level difference-in-differences analysis to estimate the impact of the 2016 California policy on vaccination coverage and prevalence of exemptions to vaccine requirements (nonmedical and medical). We used publicly available state-level data from the US Centers for Disease Control and Prevention on coverage of measles, mumps, and rubella (MMR) vaccination, nonmedical exemption, and medical exemption in children entering kindergarten. We used county-level data individually requested from state departments of public health on overall vaccine coverage and exemptions. Based on data availability, we included state-level data for 45 states, including California, from 2011 to 2017 and county-level data for 17 states from 2010 to 2017. The prespecified primary study outcome was MMR vaccination in the state analysis and overall vaccine coverage in the county analysis.In the state-level synthetic control analysis, MMR coverage in California increased by 3.3% relative to its synthetic control in the postpolicy period (top 2 of 43 states evaluated in the placebo tests, top 5%), nonmedical exemptions decreased by 2.4% (top 2 of 43 states evaluated in the placebo tests, top 5%), and medical exemptions increased by 0.4% (top 1 of 44 states evaluated in the placebo tests, top 2%). In the county-level analysis, overall vaccination coverage increased by 4.3% (95% confidence interval [CI] 2.9%–5.8%, p < 0.001), nonmedical exemptions decreased by 3.9% (95% CI 2.4%–5.4%, p < 0.001), and medical exemptions increased by 2.4% (95% CI 2.0%–2.9%, p < 0.001). Changes in vaccination coverage across counties after the policy implementation from 2015 to 2017 ranged from −6% to 26%, with larger increases in coverage in counties with lower prepolicy vaccine coverage. Results were robust to alternative model specifications. The limitations of the study were the exclusion of a subset of US states from the analysis and the use of only 2 years of postpolicy data based on data availability.ConclusionsIn this study, implementation of the California policy that eliminated nonmedical childhood vaccine exemptions was associated with an estimated increase in vaccination coverage and a reduction in nonmedical exemptions at state and county levels. The observed increase in medical exemptions was offset by the larger reduction in nonmedical exem...

Intent among Parents to Vaccinate Children before Pediatric Vaccine Recommendations, Minnesota and Los Angeles County, California--May-September 2021

“…Legislative approaches have also increased child immunization rates. [30][31][32] Individual school districts could also add a COVID-19 vaccine mandate to the list of vaccines that are already required for most students to attend public school. 33 With political will and advocacy, more such policies could be enacted.…”

In the Wake of a Pandemic: Revisiting School Approaches to Nonmedical Exemptions to Mandatory Vaccination in the US

“…[ 36 ] Among the strongest motivations for elimination of non-medical exemptions is evidence that elimination of non-medical exemptions leads to increased vaccination rates. [ 37 , 38 ] Conversely, increased use of non-medical exemptions decrease overall rates of immunization, which correlates with increased incidence of certain VPD. In particular, measles and pertussis outbreaks have both been associated with more permissive exemption policies.…”

The long-term success of mandatory vaccination laws at implementing the first vaccination campaign in 19thcentury rural Finland

“…Hence, to what extent vaccination laws are effective at increasing vaccination coverage is debated (24)(25)(26)(27)(28)(29). So far, preliminary studies and short-term monitoring indicate that recent vaccination laws have been successful at generating a short-term increase in vaccination coverage in Italy and France (19,21) and in California, where a recent vaccination policy eliminated nonmedical exemptions from school entry requirements (30). However, to what extent this is a general result and whether the increase lasts on the long-term remain unknown.…”