Pennsylvania Measles Cases Surpass 1,000 Amid State's Largest Outbreak in Decades
The state has reported over 1,000 cases, 198 hospitalizations, and five deaths linked to the virus, with the CDC prepared to offer assistance if requested.
Pennsylvania has recorded more than 1,000 measles cases this year, marking the state's largest outbreak in decades. The Pennsylvania Department of Health (DOH) reported Monday that the total number of cases has reached 1,004 across 39 counties.
Data from the DOH indicates that at least 198 individuals have been hospitalized due to the virus, and five measles-associated deaths have been confirmed. Among the deceased were two unvaccinated adults, an 18-year-old and a 40-year-old, as well as two infants too young to have received the measles, mumps, rubella (MMR) vaccine. A fifth death was reported in an unvaccinated resident of Lancaster County, which has emerged as the outbreak's epicenter with 391 confirmed cases.
According to DOH data, fewer than 1% of the state's cases have occurred in individuals who are fully vaccinated with the MMR vaccine. The Centers for Disease Control and Prevention (CDC) stated it was "deeply saddened to hear of another death" in Pennsylvania and noted that under Secretary Robert F. Kennedy's leadership, the agency has responded to measles outbreaks across the country. The CDC has provided assistance through Epi-Aid deployments to states including Texas, South Carolina, Virginia, Kansas, New Mexico, and Wisconsin, helping to bring their outbreaks under control.
While the CDC has not received a formal Epi-Aid request from Pennsylvania, it stands ready to deploy epidemiologists to support the state's needs if requested. An Epi-Aid is a rapid, short-term field investigation by the federal health agency to address urgent public health problems, providing resources such as increased workforce for rapid response and enhanced epidemiologic capacity.
Nationally, measles cases have surpassed 3,800 in 2026, with cases confirmed in 45 states and Washington, D.C., according to the latest CDC data. The CDC recommends two doses of the MMR vaccine for measles prevention: the first between 12 and 15 months old, and the second between 4 and 6 years old. One dose offers 93% effectiveness, while two doses provide 97% effectiveness.
Infants aged 6 to 11 months who are in or traveling to high-risk outbreak areas may receive an early, additional dose of the MMR vaccine. However, CDC data indicates a decline in vaccination rates in recent years. For the 2025 to 2026 school year, 92.4% of kindergartners received the MMR vaccine, a decrease from 95.2% in the 2019 to 2020 school year, prior to the COVID-19 pandemic.
In Pennsylvania, state health department staff have administered over 8,800 doses of the MMR vaccine, with approximately 3,500 doses given in August and over 2,500 in September.