New federal data show the U.S. is facing a sharp measles resurgence. As of Oct. 22, there have been more than 4,580 cases nationwide in 2026—over twice the total for 2025—according to the Centers for Disease Control and Prevention (CDC), as reported by NPR. Pennsylvania officials say the state has been hit hardest.
Pennsylvania’s toll, per state health officials
The Pennsylvania Department of Health reported at least 1,338 confirmed cases across 44 counties so far this year, including 21 new cases as of Oct. 21. The department said more than 250 people have been hospitalized and five people have died; three of the five deaths were residents of Lancaster County. NPR reported that local Amish communities in Lancaster and Mifflin counties—where vaccination rates are low—have been most affected.
Who is getting sick, according to CDC data
The CDC reported that 96% of people who contracted measles in 2026 were unvaccinated or had unknown vaccination status.
What officials are doing
Pennsylvania Secretary of Health Dr. Debra Bogen met with Mifflin County providers to assess needs. “Our state metrics and data tell part of the story of the measles outbreak in Pennsylvania, but listening to the people on the ground caring for people in affected communities like Mifflin County is essential to refining our public health response,” Bogen said in a department statement.
The Pennsylvania Department of Health said interest in measles vaccination has risen. More than 39,000 measles vaccine doses were administered statewide in the first three weeks of October, compared with an average of about 25,000 doses in a typical month, according to the department.
Protection: what CDC says about MMR
The CDC reports that two doses of the measles, mumps, and rubella (MMR) vaccine are nearly 97% effective against measles; one dose is about 93% effective.
Other states to watch
New York Gov. Kathy Hochul declared a disaster emergency earlier in October amid rising cases. As of Oct. 20, the New York State Department of Health reported more than 160 confirmed cases.
Utah has reported more than 700 measles diagnoses this year as of Oct. 20, according to the Utah Department of Health and Human Services, which also said there have been no new diagnoses in the past three weeks.
South Carolina has recorded at least 997 cases in 2026; the state Department of Public Health says that outbreak ended in April.
Note on evolving counts
NPR issued a correction clarifying that the 4,580 national figure reflects cases reported through Oct. 22, 2026. Case totals are updated by health agencies and may change.
