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 measles outbreak is showing no signs of slowing down and has spread to new areas in Texas for the first time

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.

Oklahoma is reporting one new confirmed measles case. The agency provided a notice for a public setting exposure site at Luigi’s Italian Restaurant & Lounge in Weatherford from 5:30 to 9 p.m. on March 19. As of Tuesday, Oklahoma has reported eight confirmed measles cases and two probable cases.

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.

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

Public Health Ontario says there are currently 52 hospitalizations related to measles cases, 10 more than last week.