Five new measles cases have been confirmed in Lancaster County since Monday, bringing the county’s outbreak total to 41 since late April and 49 for the year.
Penn State Health Lancaster Medical Center said a handful of infected adults were sick enough to need inpatient care, with complications including electrolyte abnormalities, kidney and liver dysfunction, and blood-count problems that can raise risks of organ failure, infection and bleeding.
All 84 Pennsylvania cases this year have involved people who were unvaccinated or whose status was unknown, and state officials said one measles case can infect 12 to 18 susceptible people while exposing an unvaccinated person carries a 90% infection risk.
Pennsylvania has vaccinated 430 people in the past two months, mostly in Lancaster and Lebanon, and has urged earlier shots for infants in affected counties, recommending a first dose at 6 months instead of 1 year.
Why are adults in the current measles outbreak suffering from life-threatening complications?
With measles once eliminated, what is causing the dangerous immunity gap now threatening Pennsylvania communities?
2026 Measles Crisis in Pennsylvania: Low Vaccination Rates, Policy Failures, and the Threat to Public Health
Overview
Pennsylvania is facing a serious measles crisis as of June 26, 2026, with localized outbreaks emerging in areas where vaccination rates have steadily declined over several years. Public health officials are closely monitoring communities identified as having lower immunity levels, since insufficient vaccination coverage creates fertile ground for the highly contagious measles virus to spread rapidly. This situation highlights the increased risk of widespread transmission, especially in vulnerable populations, and underscores the urgent need for improved vaccination efforts and stronger public health responses to prevent further outbreaks.