Map shows measles cases across U.S.

Just over three months into 2025, the United States has recorded the most measles cases in a single year since a 2019 wave, Centers for Disease Control and Prevention data shows. The majority of the infections have been reported in an outbreak in West Texas that has led to the deaths of two children. The number of cases in Texas alone has grown to more than 480 and continues to rise. Nationwide, cases have surpassed 600, with infections confirmed in 21 states.

Measles is one of the most contagious infectious diseases, and in some cases can cause severe infections in the lungs and brain that can lead to cognitive issues, deafness or death. But doctors and health officials say the vaccine, which is normally given as part of the combination measles-mumps-rubella (MMR) vaccine, is highly safe and effective.

While most people’s symptoms improve, about 1 in 5 unvaccinated people who get measles will be hospitalized. About 1 out of every 1,000 children with measles will develop brain swelling that can lead to brain damage, and up to 3 of every 1,000 children who become infected will die, the CDC says. 

The largest outbreak so far this year has been in West Texas, but cases have been reported in other states around the country as well. 

The CBS News data team is tracking confirmed measles cases nationwide as new data is released by state health departments and the CDC. (The map below is updated on Fridays when the CDC releases its latest weekly numbers.)

The Texas outbreak is primarily affecting children and teenagers, nearly all of whom were unvaccinated or have an unknown vaccination status. State and local health officials confirmed the first patient who died was an unvaccinated school-aged child, and the second was an unvaccinated 8-year-old girl. New Mexico also reported the death of an adult with measles.

The last measles death in the U.S. before this year was in 2019, when a 37-year-old man died from measles complicated by meningitis in California, according to CDC data.

The highest number of confirmed cases in the U.S. in recent years was 1,274 in 2019, driven by outbreaks in New York, California and Washington state, but most years the total has been much lower. 

Health experts point to lower vaccination rates as a reason for increases in preventable diseases like the measles.

CDC data shows about 93% of kindergarteners in the U.S. were vaccinated against measles during the 2021-2022 school year and only 92.7% in the 2023-2024 school year. This is down from 95.2% during the 2019-2020 school year — a critical threshold to keep people safe. 

“When more than 95% of people in a community are vaccinated, most people are protected through community immunity (herd immunity),” the CDC states.

Health and Human Services Secretary Robert F. Kennedy Jr., a noted vaccine skeptic, voiced support for the measles vaccine in early March amid the deadly outbreak in the Southwest, after previously downplaying the growing cases and making numerous false and misleading claims about the safety of the MMR vaccine.

Kennedy said he was “deeply concerned about the recent measles outbreak,” in an opinion piece published by Fox News.

“Vaccines not only protect individual children from measles, but also contribute to community immunity, protecting those who are unable to be vaccinated due to medical reasons,” he wrote.