While there are usually cases and even minor outbreaks reported yearly, the 2025 outbreak is on track to be the largest in six years.

Measles is one of the most contagious viruses known to humans, experts say. Measles has been spreading across the U.S. for the last several weeks, sickening people in at least nine states amid a growing outbreak in western Texas.

Public health experts said that although it’s true we have measles cases in the U.S. every year, the latest outbreak is concerning.

Kennedy Jr. said ending the measles outbreak in Texas is a top priority for him and listed the steps his agency had taken to combat the spread of disease, including supporting the state’s vaccine efforts.

Before there was a vaccine in 1963, measles infected millions and killed hundreds of people in the U.S. every year. Now, with the first measles death occurring in over a decade, doctors warn that declining vaccination rates are bringing the disease back,