Pennsylvania public health officials confirmed 1,286 measles cases across 42 counties this year, issuing a rare clinical alert regarding congenital measles and infections during pregnancy. State health authorities note that congenital measles cases have not been recorded in the United States for decades.
The outbreak has reached 42 counties across the Commonwealth, driven by under-vaccinated pockets and slipping immunization rates that allow the infectious virus to spread rapidly. State records show that 247 individuals have required hospitalization during the outbreak. In pop-up clinics and at state health centers combined, DOH nurses have administered more than 9,700 MMR vaccine doses to residents across the Commonwealth in 2026. Statewide, health care providers have also seen a surge of interest from residents seeking MMR vaccinations. In a typical month, Pennsylvania health care providers administer approximately 25,000 doses of the MMR vaccine.
State Response
To support local containment efforts, the Pennsylvania Department of Health continues to lead a robust response to the ongoing measles outbreak and is making the most up-to-date information on cases, hospitalizations, and deaths available on its measles dashboard. Health alerts help clinicians and the public recognize unusual infections quickly.
Without proper protection or supportive care, measles can be deadly. Symptoms can start 7 to 21 days after exposure. People are typically contagious 4 days before and 4 days after rash onset. People who believe they were exposed to measles, and are experiencing symptoms, should contact their health care provider or call DOH’s toll-free hotline at 877-PA-HEALTH (877-724-3258).
Pregnancy Risks and Clinical Guidance for Healthcare Providers
The health department issued an alert addressing an increase in measles cases during pregnancy and congenital measles. Contracting measles while pregnant increases the risk of miscarriage, early labor, and low birth weight. Babies who contract measles before or during birth can also become very sick and are at risk for health complications later in life. A case of measles during pregnancy increases the risk of hospitalization, pneumonia, the need for oxygen support or mechanical ventilation, and death. It also increases the risk of miscarriage, stillbirth, low birth weight, and preterm labor.
The MMR vaccine is not recommended during pregnancy because it is a live attenuated vaccine and poses a theoretical risk of causing an infection in a fetus. If a pregnant person is exposed to the virus, they’re recommended to receive intravenous immunoglobulin to help protect against infection—but only if it is given within six days of exposure. The virus can be transmitted to the fetus in utero or infect a child during or immediately after delivery. In infants, congenital measles may manifest as fever, jaundice, rash, low platelet levels, pneumonia, and neurological complications. Children who survive the acute infection require long-term monitoring due to the risk of immune amnesia and subacute sclerosing panencephalitis, a progressive fatal neurological disease that can occur years after infection.