Wyoming Confirms Measles Case in Park County

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Published December 19th, 2025

Detected March 17th, 2026

Summary

The Wyoming Department of Health has confirmed a case of measles in a Park County resident. The individual was fully vaccinated but had extensive exposure abroad. The department is notifying potentially exposed individuals and reminding residents to stay up to date on MMR vaccines.

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What changed

The Wyoming Department of Health (WDH) has confirmed a case of measles in a Park County resident, an adult who was fully vaccinated but experienced a mild illness after exposure abroad. The WDH is actively identifying and notifying individuals potentially exposed to the virus at specific locations and times in Cody, Wyoming. This notice serves to inform the public and reinforce vaccination recommendations.

While the case is mild and the individual was not hospitalized, the WDH is emphasizing the high contagiousness of measles and the importance of the MMR vaccine for all Wyoming residents. The department recommends ensuring vaccination status is up to date for both individuals and children. Further information and guidance for those potentially exposed are available on the WDH website.

What to do next

Review vaccination status for measles (MMR) for all residents and children.
Refer to WDH guidance for individuals potentially exposed to measles.
Ensure access to MMR vaccines through providers, pharmacies, and public health offices.

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Home » News » Measles Case Confirmed in Park County

Measles Case Confirmed in Park County

December 19, 2025

The Wyoming Department of Health (WDH) has confirmed a case of measles in a Park County resident. The adult is fully vaccinated but had extensive exposure to measles while abroad and developed a mild illness. The individual was not hospitalized. WDH is notifying all identified individuals potentially exposed to measles in Park County.

While it is rare for immunized individuals to develop measles infection, it can occur and typically results in milder illness compared to unvaccinated individuals. Of the 1,958 measles cases reported in the U.S. to date in 2025, 93% have been unvaccinated, 3% have received one dose of MMR, and 4% have received two doses of MMR.

Members of the public may have been exposed to measles at the following locations and times. The measles virus can remain in the air for up to two hours after an infectious individual leaves an area.

Albertsons, 1825 17th St., Cody, WY 82414
- December 15, 2025, 1:30 PM – 4:00 PM
- December 17, 2025, 2:30 PM – 5:00 PM
Walmart, 321 Yellowstone Ave., Cody, WY 82414
- December 18, 2025, 2:30 PM – 5:00 PM

Measles is a highly contagious virus that can cause serious illness, including pneumonia, encephalitis, hospitalization, and death. The measles, mumps, and rubella (MMR) vaccine provides highly effective and long-lasting protection against measles infection. WDH recommends that all Wyoming residents ensure they and their children are up to date on MMR vaccines. MMR vaccines are widely available in Wyoming through providers’ offices, pharmacies, and public health nursing offices.

For more information on measles, including guidance on what to do if you were exposed, visit https://health.wyo.gov/publichealth/infectious-disease-epidemiology-unit/disease/measles/.