Pennsylvania's measles outbreak has reached 1,222 confirmed cases across 42 counties, and Montgomery County's top health official is urging local residents to check whether they're protected.

Dr. Richard Lorraine, medical director for the Montgomery County Office of Public Health, delivered the warning during a presentation on vaccinations and fall illness season, first reported by Mainline Media News.

"This is something that we have not seen in many many years," Lorraine said. "Pennsylvania has turned out to be sort of an epicenter because of a large unvaccinated population."

Montgomery County Commissioners Vice Chair Neil Makhija called it the highest toll in the United States this year and the worst outbreak in Pennsylvania since 1991.

Montgomery County itself has reported three cases so far in 2026.

But Lorraine acknowledged that surrounding counties carry significant caseloads. Lancaster County leads the state with 443 cases, followed by Mifflin County with 183 and Chester County with 90, according to the Pennsylvania Department of Health's measles dashboard.

The state health department confirmed 1,222 cases as of Wednesday, Oct. 14. The department also reported five confirmed measles-associated deaths statewide and said it is investigating a sixth in Franklin County, according to WHYY.

The Mainline Media News account of Lorraine's presentation cited four deaths. The discrepancy was not explained.

About one in five people who contracted the virus have been hospitalized, state data shows. Roughly two-thirds of cases have been in adults and one-third in children, Lorraine said.

Less than 1 percent of U.S. measles cases involved vaccinated people, Lorraine said, calling the MMR vaccine "one of the safest vaccines that we have and one of the most effective vaccines that we have." One dose provides about 93 percent protection. A second dose, given around school entry, raises that to 97 percent.

Who should act

Anyone born before 1957, anyone who has had measles, or anyone with two documented MMR doses is considered immune, according to county health officials. People unsure of their status should check records, baby books, medical offices or electronic registries, Lorraine said.

Unvaccinated residents, pregnant women, people with weakened immune systems and parents of infants under 1 year old should contact a health care provider immediately if they suspect exposure.

County officials ask that anyone who suspects they have measles call their provider or the Office of Public Health at 610-278-5117 before visiting a medical facility, to reduce exposure to staff and other patients.

Free vaccines and upcoming clinic

People who live, work or attend school in Montgomery County can receive a free MMR vaccine, Makhija said. The county's Office of Public Health is offering the shot at community vaccine clinics.

The next clinic is scheduled for Monday, Oct. 19, from 3:30 to 7 p.m. at the Upper Merion Township Building, 175 West Valley Forge Road in King of Prussia, according to the Montgomery County Department of Health and Human Services. Flu and COVID-19 vaccines will also be available. Appointments can be scheduled by calling 610-970-5040.

Statewide, health care providers administered more than 56,000 MMR doses in September, more than double the typical monthly rate, according to a Pennsylvania Department of Health update reported by the River Reporter.

Residents with questions can email [email protected] or visit montgomerycountypa.gov/measles.