Pennsylvania measles outbreak approaches 800 cases, officials report four deaths

Pennsylvania's measles outbreak, the biggest in the United States for 2026, has reached approximately 792 cases, with a recent surge of nearly 100 infections in the past week. The majority of cases are concentrated in Lancaster County, which alone has reported more than 300 infections, while Chester County and Mifflin County have recorded 76 and 93 cases respectively. Four deaths have been classified as measles-associated: two infants in Lancaster County, a 40-year-old woman in Jefferson County, and an 18-year-old in Mifflin County.

State health officials are working with the CDC, seeking an Epi-Aid team, and have organized pop-up vaccination sites, including a free MMR clinic at the Bloomsburg Fair and dozens of other clinics that have delivered over 4,800 doses since April. Additional potential exposures were noted at the Children’s Hospital of Philadelphia and Philadelphia International Airport. Vaccination rates have been declining, prompting intensified outreach efforts.