As of April 25, 2025, the CDC has confirmed 884 measles cases across 30 US jurisdictions. This is a sharp increase from the 285 cases reported in 2024 and 59 cases in 2023. Of the 2025 cases, 820 (93 percent) are linked to 11 outbreaks, compared to 69 percent outbreak-associated cases in 2024.1
As we know, children account for a large share of infections. There have been 266 cases (30 percent) in children under 5 years of age, 338 cases (38 percent) in those aged 5 to 19, and 261 cases (30 percent) in adults 20 years and older. Overall, 97 percent of cases involve unvaccinated individuals or whose vaccination status is unknown.1
A total of 94 patients have been hospitalized, representing 11 percent of all cases. Among children under 5, the hospitalization rate is 20 percent. Three measles-related deaths have been reported in 2025.1
CDC data show a decline in MMR vaccination coverage among U.S. kindergartners. Coverage fell from 95.2 percent in the 2019–2020 school year to 92.7 percent in 2023–2024, leaving an estimated 280,000 children vulnerable to measles.1
Some of the new case counts are from Colorado and Los Angeles. Colorado officials reported the state's fifth measles case of 2025. The patient is an adult with confirmed MMR vaccination who recently traveled from Chihuahua, Mexico, where a measles outbreak is ongoing.2 In Los Angeles County, a new case was identified in a resident who had recently traveled from Texas. The individual was not infectious during travel, and no secondary cases have been reported. This is the county’s first case since March 2025.3