Each year, the CDC compiles and releases data on childhood immunization rates across the country by examining school-reported data on kindergarten vaccine coverage and exemption status.
Since there’s no national requirement for individual-level vaccine reporting, the best available proxy for estimating childhood vaccination rates is the percentage of kindergartners who are not exempted from school vaccine requirements. States compile and report this data to the CDC, which typically summarizes it in a Morbidity and Mortality Weekly Report (MMWR).
Instead of an MMWR summary with trend analysis and public health context, the CDC quietly released a spreadsheet (without commentary) this year listing each state’s kindergarten coverage rates for vaccines like MMR (measles, mumps, and rubella), DTaP, polio, and varicella. You can find that raw data here: CDC Kindergarten Vaccination Data 2025 (Excel Spreadsheet)
Arizona Ranks 40th of 51 in MMR Vaccine Coverage
This year’s numbers show that just 88.6% of Arizona kindergarteners are up to date on their MMR vaccines, placing Arizona 40th out of 51 (the 50 states plus D.C.). See that Chart Here.
That’s a drop of 0.6% from last year, consistent with a trend we’ve seen for more than a decade, where Arizona’s coverage falls by roughly half a percent every year.
The national picture isn’t much better, but Arizona’s continued slide is alarming—especially considering that the MMR vaccine is essential to preventing measles outbreaks, which have been on the rise globally and domestically.
ADHS Announces Positive Changes to their Vaccines for Children Program!
An Unusual Pattern in Public Health Rankings
Most public health outcomes tend to follow a familiar regional pattern: Northeastern and West Coast states (typically those with stronger public health infrastructure and progressive policy environments) perform well, while Southern states (those in the “SEC Conference” region) have the worst outcomes.
But vaccination rates is an exception.
For example:
- Mississippi, a state that usually performs poorly in health rankings, has among the highest childhood vaccination rates in the country.
- Meanwhile, Minnesota, often considered a leader in health policy, has one of the lowest vaccination rates, even worse even than Arizona.
What Explains the Difference?
Policy.
States like Mississippi don’t allow personal or philosophical exemptions to school vaccine mandates. In other words, unless there’s a medical reason, their kids need to be vaccinated to attend school.
In contrast, states like Arizona have permissive exemption policies that allow parents to opt out of school vaccination requirements for personal or religious reasons. Unsurprisingly, those states consistently rank near the bottom in vaccine coverage.
Why It Matters
The decline in vaccination rates, especially for highly contagious diseases like measles, isn’t just a bureaucratic issue. It puts entire communities at risk. MMR vaccine coverage needs to be above 90–95% to have herd immunity and prevent outbreaks. Arizona, like many other states, is now falling below that threshold.
The Bottom Line
Arizona’s persistent decline in MMR vaccination rates should be setting off alarm bells. We now rank in the bottom 20% of the country, and our trendline shows no sign of reversal. Policy decisions, especially around whether states allow personal choice exemptions are a major reason.
Thankfully, Governor Hobbs has consistently been vetoing bills that would have thrown gas on the fire.
Public health stakeholders, lawmakers, and communities need to pay attention. We know what works, no personal exemptions for school attendance.
Note: For decades, CDC published this data in the form of an MMWR report. This year, it was released only as a raw spreadsheet with no accompanying analysis or context.
