Pennsylvania Measles Outbreak Reaches 943 Cases and Five Deaths Across 39 Counties

Pennsylvania's measles outbreak has reached 943 confirmed cases across 39 counties as of September 30, 2026, according to the state Department of Health. The outbreak has resulted in five deaths and 176 hospitalizations.

The fifth death, reported September 30, involved an unvaccinated resident of Lancaster County. Earlier fatalities included two infants, a 40-year-old woman in Jefferson County, and an 18-year-old from Mifflin County who died from acute disseminated encephalomyelitis, a rare neurological condition linked to measles infection.

The outbreak began in late April 2026. Fewer than 1% of confirmed cases involved vaccinated individuals, consistent with the MMR vaccine's estimated 97% effectiveness after two doses.

The Pennsylvania Department of Health has administered more than 5,500 MMR vaccine doses through approximately 180 pop-up clinics since the outbreak began. State officials continue to urge vaccination as the primary defense against the virus.

The outbreak has also become a source of political tension. The U.S. Centers for Disease Control and Prevention has not included the Pennsylvania deaths in its national tally, citing a shift in reporting methodology. Pennsylvania Governor Josh Shapiro has criticized federal health leadership for what he calls politicizing the outbreak. U.S. Health Secretary Robert F. Kennedy Jr. denied directing the CDC to suppress the reporting of these deaths.

Health officials say the outbreak is concentrated in communities with lower vaccination rates. They are urging parents to check their children's vaccination records and consult a doctor if they are unsure of their status.