Federal health officials confirmed Friday that measles infections in the United States have exceeded 4,000 for the year, with Pennsylvania responsible for more than a quarter of all reported cases. The Centers for Disease Control and Prevention (CDC) tallied 4,080 cases across 47 states and Washington, D.C., marking the most severe outbreak the country has seen in decades.
Pennsylvania alone has recorded 1,105 infections, far outpacing the next highest state, South Carolina, which has 670. The commonwealth's outbreak is its worst in over 35 years and has triggered a public confrontation between Gov. Josh Shapiro and U.S. Health and Human Services Secretary Robert F. Kennedy Jr. over how measles-related deaths are counted.
Death Toll Discrepancy Fuels Political Fight
The Pennsylvania Department of Health reports five deaths associated with measles, while the CDC's official count lists only two. The gap has become the center of a bitter dispute between Shapiro and Kennedy, who have clashed over what criteria should be used to classify a death as measles-related. The CDC's database does not specify the location or timing of the deaths it counts, leaving it unclear whether Pennsylvania's reported fatalities are included in the federal tally. No other state has reported a measles death this year.
The CDC notes on its website that its figures are provisional, stating: “This number is subject to change. CDC will update its reporting as additional information becomes available and relevant reviews are completed.”
Vaccination and Demographics
Measles is a highly contagious virus, but two doses of the MMR vaccine offer the best protection, according to the CDC. The Pennsylvania Health Department says the two-dose regimen is 97 percent effective at preventing measles for life. The current outbreak has spread rapidly, with 42 distinct outbreaks reported in 2026 and 96 percent of confirmed cases linked to those clusters.
Children and teenagers have been hit especially hard. CDC data show that 42 percent of cases this year occurred among those aged 5 to 19, while 17 percent were in children under 5 and 40 percent were in adults over 20. For all of 2025, the U.S. recorded 2,289 cases across 45 states and Washington.
New York Declares Emergency
The outbreak's reach extends beyond Pennsylvania. In New York, Gov. Kathy Hochul declared a statewide disaster emergency on Monday—her first of 2026—as the Empire State's case count climbed to 97, up from 26 last year. The emergency declaration grants state agencies additional powers to contain the virus.
Last year, three Americans died from measles: two in Texas and one in New Mexico. The current outbreak's scale and the political friction it has generated underscore the challenges public health officials face in managing a preventable disease that had been largely eliminated in the U.S. two decades ago.
As the numbers continue to climb, the dispute over death reporting highlights broader tensions between state and federal authorities over data transparency and public health messaging. The CDC has not indicated when it will finalize its mortality figures, leaving states like Pennsylvania to defend their own counts amid a national surge.
