Following the Disneyland measles outbreak in 2015—with 125 confirmed cases in children–the theme park became a talking point in California school vaccine requirements. The California State Senate subsequently passed a bill eliminating all non-medical exemptions for mandatory childhood vaccines prior to school entry.
Kavin Patel and colleagues analyzed California Department of Education data to track the proportion of K-8 students enrolled in homeschooling vs. public education from 2012 to 2020 to determine the bill’s effects on homeschool rates. While the new immunization requirements began in 2016, the research team noted that the growth of homeschooling was already well underway. This study found no change in the growth of homeschooling associated with the change in vaccine requirements.
Kindergarten student vaccination rates increased from 92.8% to 95.1% following the new law. But medical exemptions for public school students almost tripled after the law changed. But as shown in the figure above, vaccine-hesitant parents were unlikely to pull their child from in-person schooling. School officials suspect many of the new medical exemptions were fraudulent.
The elimination of nonmedical exemptions for vaccines in California schools was not associated with an increase in homeschooling rates, suggesting this policy has been mostly effective in increasing vaccination rates. In response to the increase in medical exemptions, California passed another bill tightening requirements for medical exemptions from vaccines. It went into effect in 2021, so further research will determine if California can continue to increase vaccination rates.
Databyte via Kavin M. Patel, SarahAnn M. McFadden, Salini Mohanty, et al. Evaluation of Trends in Homeschooling Rates After Elimination of Nonmedical Exemptions to Childhood Immunizations in California, 2012-2020, JAMA Network Open, 2022.