Pennsylvania has recorded its first five measles cases of 2026, all in Lancaster County, among unvaccinated school-aged children and young adults. The Pennsylvania Department of Health confirmed the cluster, making this the first outbreak in the state this year and the first instance in 2026 involving three or more linked cases in one location. Four of the infections are connected locally, while one appears to be travel-related and not linked to the others, according to official health advisories.
Public health investigators moved into contact-tracing operations, identifying and notifying people who may have been exposed during the patients’ contagious period. The Department of Health issued guidance to healthcare providers to watch for measles symptoms, including fever and rash, particularly in patients who are unvaccinated or under-vaccinated.
Local school districts and medical clinics in Lancaster County began distributing exposure notices to families. Those messages urged anyone who may have been exposed to monitor closely for early symptoms and to call ahead before visiting a doctor’s office, clinic, or hospital to prevent possible transmission in waiting areas.
The Lancaster outbreak is occurring during a nationwide rise in measles. The Centers for Disease Control and Prevention reports 733 confirmed cases across more than 20 states in 2026 as of February 5, putting the United States at risk of losing its measles-free designation. In many recent outbreaks, most cases have involved people who were either unvaccinated or whose vaccination status is unknown, showing how gaps in community immunity fuel disease spread.
Public health professionals have linked this pattern directly to vaccine hesitancy and widespread misinformation about the measles, mumps, and rubella (MMR) vaccine. Dr. Joseph Aracri, chair of the Allegheny Health Network Pediatric Orthopaedic Institute, spoke plainly about the consequences.
“We can save lives by just getting vaccinated,” Dr. Aracri said. “There’s so much misinformation out there about the vaccine that people are not getting vaccinated, and now we’re seeing an emergence of the disease.”
He pointed to extensive research conducted in multiple countries involving millions of children.
“There has been no indication whatsoever that this vaccine is associated with autism and has been studied in many countries, with millions of children in the study,” Dr. Aracri said.
Despite that body of evidence, false claims about the MMR vaccine continue to discourage some parents from vaccinating their children, creating vulnerable pockets of the population where outbreaks can spread.
Health officials have been clear about why measles remains so dangerous. It is among the most contagious viruses known — up to 90 percent of susceptible people exposed to the virus can become infected. The disease typically begins with high fever, cough, runny nose, and red, watery eyes, followed by a distinctive red rash that spreads across the body.
Complications can escalate quickly, especially for those without vaccination protection. According to the CDC, one in five people with measles may require hospitalization. Possible complications include pneumonia, encephalitis (brain swelling), long-term neurological problems, and death. In rare cases, individuals can later develop subacute sclerosing panencephalitis (SSPE), a serious condition that can appear years after infection.
Dr. Aracri described how rapidly the illness can worsen.
“Things like pneumonia, long-term breathing problems. If you do get the brain infection, you can have cognitive or seizure problems that will last,” he said.
There is no specific treatment for measles. Healthcare providers can only manage symptoms with supportive care such as Tylenol and hydration, while the patient’s immune system fights the virus.
Vaccination offers strong protection by comparison. Two doses of the measles vaccine decrease the chance of contracting the disease by 97 percent, and symptoms remain very mild for the 3 percent who become infected after vaccination.
“I don’t think it’s a status thing. I think it’s a public health thing,” Dr. Aracri said. “It’s a shame to see people get seriously ill and possibly die from a disease that is completely preventable.”
In response to the Lancaster cases, the Pennsylvania Department of Health issued a statewide “Health Alert” to healthcare providers. The advisory called for immediate reporting of suspected measles cases, heightened clinical awareness of symptoms, and stricter infection prevention measures in medical settings to reduce spread.
The Allegheny County Health Department, which oversees western Pennsylvania, including Pittsburgh, confirmed that it currently has zero local measles cases. Officials said they are closely monitoring the situation and participating in coordination calls with state and federal partners. The department is offering MMR vaccinations and testing as part of its preparedness efforts.
Health departments across Pennsylvania have prepared response procedures in case additional outbreaks occur, including isolation measures for infected individuals, quarantine recommendations for exposed people, and community education campaigns.
With spring travel and gatherings approaching, public health experts are urging families to review their vaccination records. The standard MMR schedule includes a first dose at 12 to 15 months of age and a second dose at 4 to 6 years old. Healthcare providers can administer early doses to infants as young as 6 months in specific exposure situations.
Dr. Aracri made a direct appeal to families who have avoided vaccination.
“There’s no reason for anybody to get significantly sick or die from it,” he said.
Before widespread vaccination programs, measles killed hundreds of children each year in the United States and caused serious complications in thousands more.
Health officials in Pennsylvania and at the CDC are continuing to track cases, expand public education, and provide updated guidance on testing and infection control. The CDC has warned that sustained measles transmission could threaten the nation’s measles-free status.
Parents and guardians who are unsure about their family’s vaccination status are being advised to consult their healthcare providers about the MMR schedule. Anyone who develops measles-like symptoms is encouraged to seek medical advice promptly, but to call clinics ahead of time before visiting to limit exposure to others.
