The percentage of kindergarteners whose parents opted them out of school-required vaccinations rose to the highest level yet during the 2022-2023 school year, according to new federal data released Thursday.
The drop in coverage for routine vaccinations against diseases like measles, mumps, and rubella increase the chances of an outbreak, and underscore the continued fallout from barriers to vaccination during the COVID-19 pandemic.
An outbreak of measles in central Ohio last winter brought renewed attention to the risks of not completing MMR vaccinations. The CDC found that 94 percent of the cases occurred in children under 5 years of age who were unvaccinated.
This kindergarten class became age-eligible to complete most state-required vaccinations during the COVID-19 pandemic. Every state and the District of Columbia requires children to get vaccinated against certain diseases before they start school, including measles, mumps, polio, tetanus, whooping cough and chickenpox.
“Because clusters of undervaccinated children can lead to outbreaks, it is important for immunization programs, schools, and providers to make sure children are fully vaccinated before school entry, or before provisional enrollment periods expire,” CDC said in the report.
National coverage remained near 93 percent for all vaccines, similar to the 2021–22 school year, lower than the 94 percent coverage in the 2020–21 school year, and lower still than the 95 percent coverage during the 2019–20 school year, when children were vaccinated before the COVID-19 public health emergency.
All states grant exemptions for religious reasons, and some for philosophical reasons too.
Exemptions were low overall, CDC said, but still hit the highest ever recorded at 3 percent, compared with 2.6 percent during the 2021–22 school year.
Exemptions increased in 40 states and D.C., and ten states reported more than 5 percent of kindergartners were exempted from at least one required vaccine.
Idaho had the highest percentage of exemptions overall, with 12 percent of kindergartners receiving at least one exemption. In contrast, only 0.1 percent of kindergarteners in New York were exempted.
The CDC recommends two doses of the MMR vaccine, with the first dose administered between 12 and 15 months of age, and the second doses be administered between 4 and 6 years of age.
National MMR coverage among kindergarten students remained below the Healthy People 2030 target of 95 percent for the third consecutive year.
The report did not look at reasons why vaccination coverage has been declining.
“It is not clear whether this reflects a true increase in opposition to vaccination, or if parents are opting for nonmedical exemptions because of barriers to vaccination or out of convenience,” CDC officials wrote. “Whether because of an increase in hesitancy or barriers to vaccination, the COVID-19 pandemic affected childhood routine vaccination.”
Still, the politicization of COVID-19 vaccines led to anti-vaccine sentiment being magnified.
The report’s authors said a “better understanding of the reasons behind nonmedical exemptions increasing in 40 states and DC, and their impact, could help develop policies … to bring higher vaccination coverage and protection against vaccine-preventable diseases within reach of more states.”