The number of school-aged children who received exemptions for childhood vaccines rose to a record high last year, according to a new report from the Centers for Disease Control and Prevention.

Of children entering kindergarten in the 2025-26 school year, 4.2% received exemptions for at least one vaccine. That's up from 3.6% the previous year. The increase in exemptions comes amidst rising measles outbreaks and the Trump Administration's pushback against mandating childhood vaccines.

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Only 92.4% of kindergarteners had received the measles, mumps and rubella vaccine last school year — well below the 95% needed for herd immunity against measles.

Measles outbreaks have spiked across the country, with more than confirmed 2,600 cases in 47 jurisdictions this year. Last year, there were 2,289 confirmed cases in 45 jurisdictions, according to CDC figures.

Last week, President Donald Trump signed an executive order lowering the recommended number of childhood vaccines from 17 to 11. The CDC attempted to institute the same vaccine schedule in January, but a court ultimately blocked the decision.

This reduced childhood vaccine schedule also calls for separating the measles, mumps and rubella vaccine into separate shots given at varying times. This is despite the MMR vaccine having long been proven safe to give as one shot. Separate vaccines against the illnesses are not available in the United States, and public health authorities have said it would take years for them to become available, according to NPR.

The CDC report shows 41 states and Washington, D.C. had increased vaccine exemptions, with 24 states reporting exemptions higher than 5%. All 50 states, plus Washington, D.C. and Puerto Rico, require proof of certain vaccinations for children entering kindergarten to help prevent the spread of communicable diseases throughout the larger population.

The majority of exemptions last school year were for non-medical reasons.

The rate for diphtheria, tetanus and acellular pertussis vaccine (DTaP) also dipped slightly to 92% for the 2025-2026 school year, from 92.1% for the 2024-2025 school year. Vaccine rates for varicella, or chickenpox, fell to 93.4% from 94%.

Health and Human Services Secretary Robert F. Kennedy Jr. has been a longtime vaccine critic and last year fired all of the 17 members of a committee of medical experts designed to advise the federal government of vaccine policy, replacing them with his own picks.