Measles Cases Rise In Arizona As Vaccination Rates Drop

Measles, once nearly eliminated, is once again a growing concern as cases rise in Arizona. Officials are becoming increasingly worried about the uptick.

The measles vaccine has been in use since 1963 and has prevented millions of deaths worldwide. Before vaccination was widely used, nearly every U.S. child had the measles by age 15. This caused hundreds of deaths and thousands of hospitalizations each year.

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Measles is Extremely Contagious

Measles is one of the most transmissible viruses. The CDC reports that 90% of unvaccinated people exposed will become infected, and the virus can linger in the air for up to two hours after an infected person leaves a room.

If you’re infected with measles, you can spread the virus without even knowing you’re sick. People are contagious for 4 days before and after the rash appears, making it extremely difficult to contain.

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Measles Cases are Rising in Arizona

The rise in measles cases in Arizona has public health officials worried. There’s a larger, national trend of declining childhood vaccination rates, and the effects are rippling across our state.

According to the Arizona Department of Health Services (ADHS), multiple counties, including Mohave, Maricopa, Pinal, and Pima, have confirmed cases early this year. Outbreaks of the illness are linked to both international travel and to areas in the state with low vaccination coverage.

Uptick In Measles Cases Across Arizona

Measles cases have surged in Arizona. There have been 12 confirmed infections across four counties in just the first three weeks of 2026.

According to state health officials, the most recent cases are linked to an ongoing outbreak in Mohave County, where vaccination rates are among the lowest in the state. Nationally, the CDC reports more than 1,700 measles cases so far in 2026, making Arizona one of the most affected areas in the country.

READ MORE: 'Too Risky!' Reason AZ Could See A Dangerous Measles Outbreak

Why Childhood Vaccination Rates Are Dropping

Routine childhood vaccination rates have been falling since the COVID-19 pandemic. Public health experts say it’s a storm of misinformation, distrust in institutions, and pandemic‑related disruptions in healthcare access.

In Arizona, only 88.7% of kindergarteners completed the MMR series in the 2024–25 school year. That’s well below the 95% needed for herd immunity.

For herd immunity to be effective, enough people in the community need to be immune, and that’s typically achieved through vaccination. Reaching recommended levels helps contain and prevent the spread of most illnesses.

Since it’s so contagious, for measles the threshold for herd immunity is extremely high: more than 95% of people must be vaccinated to stop outbreaks.

Infants, immunocompromised individuals, and those who cannot be vaccinated are at greatest risk of contracting measles, and the outcome can be extremely dangerous.

Vaccine Hesitancy: The Fallout for Arizona

Vaccine hesitancy, fueled by misinformation and fear, is allowing the virus to regain ground. The fallout is growing with more outbreaks, more hospitalizations, and greater risk to communities with low vaccination rates.

The measles vaccine has a long track record of safety and effectiveness. If you’re worried about vaccines, it’s best to talk with a qualified healthcare professional.