More than 600 measles cases have been confirmed in 20 states across the U.S. as of Friday, according to health officials, with much of the outbreak remaining centered in northwest Texas. There are 607 confirmed measles cases in the U.

The US has reported over 600 measles cases in 2025, doubling last year's total. Texas leads with 481 cases, as outbreaks spread in undervaccinated communities across several states, alarming health officials.

State health officials worry that declining vaccination rates have left many communities vulnerable nationwide.