Pennsylvania’s measles outbreak has surpassed 1,400 confirmed cases, with hundreds of patients hospitalized and cases now reported across much of the state.
The Pennsylvania Department of Health reported Oct. 30 that the state had reached 1,426 confirmed measles cases across 44 counties, including 28 newly confirmed cases since Oct. 28. Pennsylvania has recorded 268 hospitalizations and five confirmed measles-associated deaths in 2026.
The outbreak also remains part of a much larger national resurgence. The Centers for Disease Control and Prevention reported 4,852 confirmed U.S. measles cases as of Oct. 29, with 96% of cases associated with outbreaks.
Here’s what Pennsylvanians should know about the ongoing outbreak and how health officials are responding.
How many measles cases are in Pennsylvania?
Pennsylvania’s outbreak has continued to expand since late summer.
On Aug. 28, state health officials reported 460 cases across 31 counties and 83 hospitalizations. By Sept. 30, Pennsylvania had reached 943 cases across 39 counties and 176 hospitalizations.
The total reached 1,360 cases and 258 hospitalizations by Oct. 26 before climbing to 1,426 cases and 268 hospitalizations by Oct. 30.
The latest state report says only four confirmed cases were among vaccinated individuals, representing less than 1% of Pennsylvania’s cases.
Why does Pennsylvania have the most measles cases in the US?
Pennsylvania has emerged as the nation’s leading measles hotspot in 2026.
Federal surveillance data compiled from CDC weekly reports through the week ending Oct. 24 listed Pennsylvania with 1,335 measles cases, the highest total in the country, followed by South Carolina with 686 and Utah with 532.
Pennsylvania’s total has continued rising since that federal snapshot.
The comparison requires some care because state and federal reports can reflect different reporting dates. The CDC also says states have the most up-to-date information about cases and outbreaks within their jurisdictions.
Still, the available federal state-by-state data clearly puts Pennsylvania at the top of the 2026 case count.
How serious is Pennsylvania’s measles outbreak?
Measles is highly contagious and can cause serious complications.
The National Foundation for Infectious Diseases says up to nine out of 10 unvaccinated people exposed to measles can become infected, while one infected person can transmit the virus to 12 to 18 others.
Pennsylvania health officials say measles can cause serious short- and long-term health problems including pneumonia and brain swelling.
The state continues working with CDC personnel on the outbreak. A CDC Epidemic Intelligence Service officer assisting with advanced epidemiological modeling is scheduled to remain on-site through Nov. 6, according to the Health Department.
How can Pennsylvanians protect themselves from measles?
Vaccination remains the state’s primary recommendation.
Pennsylvania health officials say the two-dose measles, mumps and rubella, or MMR, vaccine provides 97% lifetime protection against measles. People with two documented doses don’t need another dose, while adults with only one dose or who can’t locate their vaccination records should talk with a health care provider or pharmacist.
Vaccination demand has risen during the outbreak. Pennsylvania providers typically administer about 25,000 MMR doses per month, but more than 56,000 doses were administered in September and more than 53,000 during the first four weeks of October, according to the state.
Residents who believe they were exposed to measles and are experiencing symptoms should contact their health care provider or call the state health hotline at 877-PA-HEALTH (877-724-3258).
