Pennsylvania Measles Outbreak Grows by 55 Cases, Death Toll Disputed

Pennsylvania's measles outbreak grew by 55 cases in the days since last Wednesday, state health officials said, pushing the confirmed total toward 900 infections spread across 39 counties, according to a report published Sept. 26.¹

Outbreak reaches record scale

Pennsylvania has recorded 890 measles cases this year across 39 counties, with Lancaster County accounting for 359 of them, the highest in the state. The outbreak has led to 173 hospitalizations and four deaths. Health officials say 31% of cases are among people younger than 18, and fewer than 1% of cases have occurred among vaccinated individuals.¹

Nationally, more than 3,659 confirmed measles cases had been reported in the United States as of Sept. 24, compared with 2,289 for all of 2025, marking a substantial year-over-year increase.¹

By Sept. 29, the Pennsylvania Department of Health reported the state total had risen to 903 cases, 176 hospitalizations and four deaths across the same 39 counties, with officials continuing outreach through pop-up MMR vaccination clinics.⁸

Dispute over the death toll

Pennsylvania has reported four measles-associated deaths this year, but the Centers for Disease Control and Prevention did not include all of them in its national tally for weeks. The CDC's national count has stood at two deaths from 3,659 cases, according to Al Jazeera and the Detroit News. Health Secretary Robert F. Kennedy Jr. has maintained that only one Pennsylvania death was caused by measles.³⁷⁴

The dispute became public after Pennsylvania Governor Josh Shapiro accused Kennedy of spreading vaccine misinformation, saying he "spread misinformation about vaccine safety that's contributed to a decline in measles vaccination rates." Kennedy responded that Shapiro had "fabricated the Lancaster County deaths," before later acknowledging that one death was measles-caused and accusing Shapiro of "politicizing the issue." State officials said at one point they were "not aware of which death the CDC is citing."⁴

The CDC initially said "available information does not establish whether measles caused or contributed to the deaths," before updating its explanation to say the National Center for Health Statistics had no 2026 death records listing measles as the underlying cause. Former CDC officials noted the agency departed from standard protocol by relying on NCHS data rather than the usual National Notifiable Diseases Surveillance System. The CDC is currently collaborating with state epidemiologists to establish a uniform way of classifying measles-related deaths, and it has said its data remain "subject to change and the agency will update its reporting of deaths as additional information becomes available."³⁷⁴

Vaccination rates and elimination risk

Pennsylvania health officials note that the MMR vaccine confers 97% lifelong immunity against measles, while roughly one to three fatalities are expected for every 1,000 people infected. State data show 93.2% of Pennsylvania kindergarten students have received both MMR doses, though a significant number of the state's schools remain below the 95% vaccination rate recommended by public health experts to sustain community immunity. Nationally, two-dose MMR coverage among kindergarteners fell to 92.5% in 2024, down from 94.7% in 2011, and only 10 states reported coverage at or above 95% in the 2024-2025 school year.⁶²

The United States achieved measles elimination status in March 2000 and had that status re-verified in 2012. The Pan American Health Organization placed the country in a category described as "sustained with major concerns" in November 2025. A KFF analysis found that, should the current trajectory continue for the balance of the year, there would seem to be sufficient justification for the U.S. to lose measles elimination status."²

State response

In the spring, Pennsylvania's health department released guidance allowing MMR vaccinations for infants as young as six months. By late September, nearly 1,000 school nurses had attended medical briefings and the department had launched a school vaccination resource tool, alongside pop-up MMR clinics across affected counties. Officials noted the state had not recorded a measles-associated death since 1991 before this year's outbreak.⁶⁸

Pennsylvania Secretary of Health Debra Bogen said, "The measles virus spreads quickly and easily to anyone who is not immune," adding, "If you are not protected or immune, you are at risk of getting measles." Michael D. Barber, chief executive of Penn Medicine Lancaster General Health, said, "The continued presence of measles is a sober reminder of why vaccination matters." Jeffrey Martin, a family medicine physician and department chair at the same health system, said, "The MMR vaccine is highly effective and remains one of the safest and most important tools we have."⁶