With Colorado’s third confirmed case of measles reported in 2026, state public health officials say getting vaccinated is the most effective way to protect against the virus.

The case, announced Monday, involves a second student at Broomfield High School to contract measles, according to the Colorado Department of Public Health and Environment and the Adams County Health Department. Neither of the two infected students had received the measles, mumps, and rubella vaccine. All three of Colorado’s confirmed measles cases in 2026 occurred in children 5-17 years old.

People at the high school between Feb. 24 and Feb. 27 could have been exposed and could see symptoms develop through March 20. Other locations where people could have been exposed are updated on CDPHE’s website, which lists exposure sites in Broomfield, Denver, Lafayette, Littleton Louisville and Westminster. Anyone at any of the locations during the exposure window should contact their health care provider.

Symptoms of measles include fever, cough, runny nose, red eyes, and a rash that typically starts several days after other symptoms. The viral disease is extremely contagious and can be deadly.

“You can protect your loved ones, yourself, and the community against measles by making sure you are up to date on your measles, mumps, and rubella (MMR) vaccine,” CDPHE recommends.

CDPHE offers online guides in English and Spanish explaining how families can prepare for measles at their children’s school or child care facility. Children attending school or day care are required by state law to have the MMR vaccine unless they have a medical or non-medical exemption on file at the school. If a measles case occurs at a school, children with exemptions on file could be required to stay home for at least 21 days.

All health insurance providers, including Medicaid and Medicare, cover the MMR vaccine. CDPHE has an online tool to find local vaccine providers.

Colorado reported six cases of measles between 2014 and 2024, and 36 cases in 2025.

The U.S. has already seen more than 1,000 measles cases in 2026, nearly half of what it saw in 2025. Health and Human Services Secretary Robert F. Kennedy Jr. has spent decades spreading misinformation and conspiracy theories about vaccines and other health issues. Health officials say declining vaccine rates are to blame for the rising measles case numbers.