Pennsylvania confirms two additional measles-associated deaths

Pennsylvania health officials have confirmed two additional measles-associated deaths, bringing the state’s total to four measles-related fatalities in 2026 and marking the deadliest measles outbreak in Pennsylvania in more than 35 years. The newly reported deaths occurred in unvaccinated residents of Jefferson and Mifflin counties, according to the Pennsylvania Department of Health (DOH).

State officials said extensive investigations were conducted in collaboration with local coroners to verify laboratory-confirmed measles infection and determine that the deaths were not attributable to unrelated causes. The announcement follows two previously reported measles-associated deaths in Lancaster County in August.

Pennsylvania has reported 693 confirmed measles cases across 38 counties so far this year, reflecting what state Health Secretary Dr. Debra Bogen described as the Commonwealth’s worst measles outbreak in more than three decades. Both state and federal health officials continue to stress that vaccination remains the most effective preventive measure. The Pennsylvania DOH notes that two doses of the measles-mumps-rubella (MMR) vaccine provide approximately 97% protection against measles.

The report comes as measles activity remains elevated nationally. According to CDC, more than 3,100 confirmed measles cases have been reported in the US in 2026, with 95% linked to outbreaks and the vast majority occurring in people who were unvaccinated or whose vaccination status was unknown.

Notably, CDC has not yet classified any U.S. measles deaths in its national 2026 surveillance data. The agency said it is working with the Council of State and Territorial Epidemiologists to develop a standardized definition for measles-related deaths and will update its reporting as reviews are completed.

Measles remains one of the most contagious infectious diseases. Pennsylvania officials noted that the virus can linger in the air for up to two hours after an infected individual leaves an area and can lead to serious complications, including pneumonia and encephalitis. Clinicians should maintain a high index of suspicion in patients presenting with fever, cough, coryza, conjunctivitis, and a subsequent descending rash, particularly in unvaccinated individuals or those with known exposure.

Sources: Pennsylvania Department of Health. (2026 Sep 15). DOH Confirms Two Additional Measles-Associated Deaths; CDC. Measles Cases and Outbreaks. Updated September 4, 2026.