Pennsylvania's MMR vaccination rate fell below 95%. Now two residents have died from measles

Two Pennsylvania residents have died from measles, marking the state's first measles-related deaths in 35 years as cases continue to rise across the Commonwealth.

Health officials said Tuesday that both people were unvaccinated residents of Lancaster County. The Pennsylvania Department of Health did not release additional information about the victims, citing privacy concerns.

The deaths come as Pennsylvania has reported 393 measles cases across 28 counties in 2026, underscoring how quickly the highly contagious virus can spread when it reaches communities with lower vaccination coverage.


"Because measles was largely eliminated in the Commonwealth for more than three decades, people are not familiar with this disease and don't fully understand the potential severity of the illness," Pennsylvania Health Secretary Debra Bogen said.

The outbreak is part of a broader resurgence of measles across the United States. The Centers for Disease Control and Prevention had recorded 2,777 confirmed U.S. cases as of August 20, making 2026 the worst year for measles infections since the major resurgence between 1989 and 1991.

That earlier period saw more than 55,000 infections and 123 deaths.

Why the 95% vaccination rate matters

The Pennsylvania deaths come as newly released school immunization data show that dozens of schools across northeastern and central Pennsylvania have kindergarten MMR vaccination rates below 95%, with several reporting rates of 80% or lower.

The 95% figure is an important benchmark for measles because the virus is exceptionally contagious. Public-health experts estimate that roughly 95% of a population needs immunity to prevent sustained transmission.

When vaccination coverage falls below that level, pockets of vulnerable people can allow the virus to spread more easily after an infected person enters a community.

That makes school vaccination data particularly important because children are among those most affected by measles outbreaks.

What makes measles so dangerous?

Measles is a highly contagious viral infection that spreads through the air when an infected person coughs, sneezes or breathes. The virus can cause complications including pneumonia and brain swelling.

According to Pennsylvania health officials, nearly 20% of people who contract measles are hospitalized. Deaths remain uncommon but can occur, with the Pennsylvania Department of Health estimating that roughly one to three people die for every 1,000 measles cases.

The MMR vaccine is typically administered in two doses during childhood, around ages 1 and 5. Adults and teenagers who are not fully vaccinated are also advised to ensure they are up to date.

Is the MMR vaccine safe?

The MMR vaccine has been used in its current form since 1971 and has been administered to millions of people.

Serious reactions are rare, while vaccination has played a major role in reducing measles, mumps and rubella in the United States.

Before the measles vaccine was introduced in 1963, an estimated 3 million to 4 million Americans contracted measles every year, resulting in about 500 deaths and 48,000 hospitalizations annually.

U.S. measles cases have reached a decades-high level

The Pennsylvania deaths come after U.S. measles cases surpassed the previous year's total.

CDC data show that 93% of reported cases in 2026 occurred among unvaccinated people, while nearly 69% involved children and teenagers ages 19 and younger.

The country had already experienced a 30-year high in 2025, when 2,289 confirmed cases were reported across 43 states and Washington, D.C. Nearly 90% of those infections were connected to 48 known outbreaks.

Three people, including two children, died during the 2025 outbreaks, marking the first pediatric measles deaths in the United States in a decade.

For Pennsylvania, however, the latest deaths carry another distinction: the state had gone 35 years without a reported measles death. The return of fatal cases is a reminder of how quickly a disease once considered largely eliminated can regain a foothold when immunity levels decline.