TUESDAY, Nov. 5, 2019 (HealthDay News) -- Assuming the current rates of medical exemptions persist, the overall exemption rate in California schools is expected to stabilize at 1.87 percent by 2027, according to a research letter published online Nov. 5 in the Annals of Internal Medicine.
Paul L. Delamater, Ph.D., from the University of North Carolina at Chapel Hill, and colleagues obtained available data on vaccination among kindergartners and seventh graders for 2009 to 2018. For each year from 2015 to 2027, the exemption status of all California schoolchildren was estimated using a grade-cohort approach considering three scenarios: current exemption use continuing (base-case scenario); the potential effect of Senate Bill 276 (SB276) increasing scrutiny on medical exemptions; and a hypothetical scenario in which SB277, which banned nonmedical exemptions from school-entry vaccine mandates, was not implemented in 2015.
The researchers found that the percentage of schoolchildren with any exemption decreased by 0.72 percentage points in the base-case scenario, from a pre-SB277 level of 2.59 percent to a stabilized rate of 1.87 percent. The percentage with any exemption decreased from 2.19 percent in 2018 to 1.41 percent in 2027 in the SB276 scenario. In the no-SB277 scenario, the percentage with any exemption decreased from 2018, stabilizing at 2.36 percent in 2021.
"Several states have recently passed or are considering legislation banning nonmedical exemptions," the authors write. "By evaluating SB277 in California, we demonstrate how these efforts can be mitigated by persistent vaccine hesitancy and the availability of alternate pathways to avoid vaccination."