Chester County measles cases expected to increase as officials urge vaccination

July 24, 2026 - 02:39

Health officials in Pennsylvania are warning that the number of measles cases in Chester County will likely continue to climb, as the highly contagious virus spreads through unvaccinated communities. The outbreak is part of a broader trend, with new infections also reported in Delaware and other states across the country.

As of this week, local health departments have confirmed multiple cases in Chester County, primarily among children and young adults who were not immunized. Officials say the virus is spreading through close contact in schools, daycares, and households. They expect more cases to surface in the coming days as contact tracing continues.

Measles is a serious respiratory illness that can lead to pneumonia, brain swelling, and even death. It is highly contagious, lingering in the air for up to two hours after an infected person leaves a room. The Centers for Disease Control and Prevention reports that about one in five unvaccinated people who get measles will be hospitalized.

Health officials are urging everyone who is eligible to get the measles, mumps, and rubella (MMR) vaccine. Two doses of the vaccine are about 97 percent effective at preventing measles. The vaccine is safe and widely available at doctor's offices, clinics, and pharmacies.

The current outbreak mirrors a national rise in measles cases, driven largely by gaps in vaccination coverage. The CDC has recorded hundreds of cases this year, many tied to international travel and spread within under-vaccinated communities. Officials stress that vaccination is the best way to protect individuals and the community from further spread.