So far in 2025, the U.S. has seen its most measles cases in one year since a wave in 2019, according to data from the Centers for Disease Control and Prevention. At least 20 states have confirmed cases, but most infections are linked to an outbreak in West Texas, according to the CBS News data team.

Tennessee has four confirmed measles cases, and health care experts know with certainty that means more are on the way. Measles was declared eliminated from the United States in 2020, but it is surging again as parents decline to vaccinate their children.

KENT COUNTY, Mich. – Michigan has confirmed its second measles case of 2025 in an adult in Kent County. The health department said the infected adult had recently traveled abroad before returning to the U.S. and traveling between Michigan and New Jersey.

The West Texas Measles outbreak is often labeled the worst in more than 30 years. TPR looked into what happened 36 years ago and what we can learn from it.

As measles spreads across the U.S., a few fully vaccinated people have contracted rare breakthrough cases. Here's what to know and why vaccination is still important.

The measles outbreak in western Texas is continuing to grow with a total of 422, according to new data published Tuesday.

As the state continues to track cases of measles in Oklahoma, they’re mindful of exposure to the virus as well.

The Tennessee Department of Health confirmed three additional measles cases in Middle Tennessee on Tuesday, less than two weeks after the region reported its first case. One of the new cases confirmed Tuesday is related to Tennessee's first confirmed case on March 21. No additional details are available about Tennessee’s positive cases.