Colorado's childhood vaccination rates slip lower
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Colorado's vaccination rates for kindergartners dipped across the board in the 2025-26 school year, while exemptions continued their post-pandemic rise, new CDC data shows.
Why it matters: Colorado's vaccination rates are among the nation's lowest, and public health officials worry about the possibility of outbreaks at schools and beyond.
By the numbers: Last school year, Colorado kindergartners' measles, mumps and rubella (MMR) coverage was 87.7%.
- Polio was 87.3%
- Diphtheria, tetanus and acellular pertussis (DTaP) was 86.9%.
- Only hepatitis B topped 90%.
The number of parents claiming exemptions rose to 4.7%, or roughly 2,800 children, CDC data shows.
- The vast majority were non-medical exemptions, which remain accessible despite efforts to limit them.
The intrigue: Herd immunity is 95% coverage for core vaccines, such as MMR, per public health officials.
What they're saying: Colorado officials are working to improve immunization rates by sending reminders via text and email and taking a mobile vaccine bus to dozens of school-focused events.
Yes, but: Obstacles remain, Rachel Herlihy, a state epidemiologist, tells us. Multiple factors are driving the numbers lower, but misinformation is key.
- "I think there's been growing confusion for parents about where to find trusted sources of information about vaccinations," she said in an interview.
- "They're hearing multiple competing voices that are saying different things."
The big picture: The CDC reported the data showed a 0.1% decline in vaccination coverage among children entering kindergarten.
- Colorado's vaccination rates for DTaP and polio are the fifth lowest in the nation among states that report the data. For MMR, the state is sixth lowest, an Axios analysis finds.
The nationwide drop-off coincided with continued efforts by the Trump administration to make vaccine policy changes and measles cases hitting levels not seen in more than three decades.
- The MMR, DTaP, polio and varicella (chickenpox) immunizations decreased in more than half of states.
- 24 states reported exemptions exceeding 5%.
Zoom in: Kari Torres, the El Paso County Public Health Immunization Clinic program manager, said rates remain stable with small declines in MMR, varicella and DTaP vaccinations.
- "Having this protection enables students to attend school and parents to work," Torres said in a statement to Axios.
- "It also protects infants who are too young for vaccines, as well as those in the community who are not able to get vaccines due to health conditions."