U.S. Measles Cases Top 4,500, More Than Double All of Last Year, as Pennsylvania Outbreak Grows

WASHINGTON, Oct. 25 (TodayViralUSA) — Confirmed measles cases in the United States this year have climbed past 4,500, more than double the total for all of 2025, as the country faces its worst resurgence of the disease in decades.

The Centers for Disease Control and Prevention reported 4,588 confirmed cases as of Oct. 22, up 178 from the previous week. Last year’s total of 2,289 cases was itself the highest since 1991. Health experts say the true number is likely higher because many cases go unreported.

Mostly unvaccinated

About 96% of this year’s cases involved people who were unvaccinated or whose vaccination status was unknown, according to CDC data. Roughly 59% of cases have been in children and teenagers, and about 10% of patients have been hospitalized, the American Academy of Pediatrics reported. The CDC has recorded 43 new outbreaks in 2026.

Pennsylvania hardest hit

Pennsylvania has the most cases of any state, with 1,338 confirmed across 44 counties, the state Department of Health said Friday. Crawford County was the latest to report a case. The state has recorded 255 hospitalizations and five confirmed measles-associated deaths, and only four cases have been in vaccinated people.

Lancaster and Mifflin counties, home to Amish communities with low vaccination rates, have been among the hardest hit, NPR reported. Three of the five people who died lived in Lancaster County. State health officials have also warned about a rise in measles during pregnancy and the risk of congenital measles.

Other states with more than 100 cases this year include South Carolina, Utah, Wisconsin, Kentucky, Texas, Virginia, Ohio, Florida, New York and Arizona, according to CDC figures cited by the AAP.

Vaccination demand rises

Two doses of the measles, mumps and rubella (MMR) vaccine are about 97% effective at preventing measles, and one dose is about 93% effective, according to the CDC.

Pennsylvania officials said interest in vaccination has jumped: more than 39,000 measles vaccines were given in the state in the first three weeks of October, compared with a typical monthly average of about 25,000.