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Across the nation, more parents are exempting their children from vaccines required for school entry — but Connecticut’s kindergarten vaccination rates have increased since the pandemic, and for one inoculation, Connecticut has the highest rate in the nation.

Vaccinations have fallen and measles cases nationwide increased, with 2025 bringing the highest number of reported cases since the disease was declared eliminated in 2000. Connecticut reported one case, and the state had the highest MMR, or measles, mumps and rubella, vaccination rates in the nation among kindergarteners for the 2024-2025 school year.

In Connecticut, 98.2% of kindergarteners received their MMR vaccine, according to CDC data. Herd immunity, a form of indirect protection against the spread of communicable disease, is met when 95% or more of a population is vaccinated. Only nine other states reached herd immunity for the MMR vaccine in the 2024-2025 school year.

Overall vaccination rates for Connecticut children have increased since 2020 after they fell during pandemic. According to a Washington Post analysis, the only other states to see this increase were Maine and Alabama.

Connecticut only allows for medical exemptions to vaccinations for school-age children after eliminating religious exemptions in 2021. The state does not allow personal exemptions. But even with these laws, some schools did not meet the 95% threshold for herd immunity.

However, many towns in the state met herd immunity for last year’s kindergarten classes. Some have very high levels of vaccination — over 98%.

While the state has high levels of childhood vaccination, seasonal vaccination rates are not as high. This flu season, according to state data as of Dec. 2, the flu vaccination rate was down 6% compared to the same time last year. There has also been an increase in flu cases and hospitalizations, and cases are far higher this year than they were the same time last year.

This overload of flu cases came just before this week’s announcement from the Trump administration overhauling the childhood vaccination schedule. The administration now no longer recommends vaccines for flu, hepatitis A, rotavirus and meningococcal disease.

Sasha is a data reporting fellow with The Connecticut Mirror. She graduated from the University of Maryland in May with a degree in journalism and a minor in creative writing. For the past year Sasha was working part time for the Herald-Mail, a newspaper based in Western Maryland. She was also a reporter and copy editor for Capital News Service, the university’s wire service where she covered the state legislature, the Baltimore Key Bridge collapse, school board elections, youth mental health and climate change. Earlier in her college career, Sasha also interned at the Baltimore Magazine and wrote for numerous student publications including the Diamondback, the university’s independent, student-run newspaper.