Pennsylvania Reports First Measles Deaths in 35 Years, Both Unvaccinated

State health officials announced the deaths in a press release Tuesday, citing privacy concerns and declining to release further details about the individuals beyond confirming they were unvaccinated and residents of Lancaster County. The Pennsylvania Department of Health did not specify whether the two cases were linked to the same outbreak or if they occurred in the same time frame.

Pennsylvania's current outbreak, which spans 28 counties, represents the largest concentration of measles cases in the state in decades. The last measles death in Pennsylvania was reported in 1991, before the disease was declared eliminated in the United States in 2000.

Nationally, the United States had not seen a measles death from 2015 until 2025, when three unvaccinated people died — two school-age children in Texas and one adult in New Mexico. Those deaths marked a dramatic reversal of decades of progress, driven largely by falling vaccination rates and increased vaccine hesitancy.

Measles is highly contagious, with a single infected person capable of spreading the virus to 90% of unprotected contacts. The disease can cause severe complications, including pneumonia, encephalitis, and death. The MMR vaccine (measles, mumps, rubella) is highly effective, with two doses providing 97% protection.

Public health experts have long warned that declining vaccination coverage — exacerbated by the spread of misinformation during the COVID-19 pandemic and amplified by anti-vaccine figures and some political leaders — would lead to the re-emergence of vaccine-preventable diseases. The current US Health and Human Services Secretary, Robert F. Kennedy Jr., has a long history of anti-vaccine advocacy, and his appointment has alarmed many public health officials.

Pennsylvania health officials urged the public to ensure they are vaccinated, noting that the outbreak is ongoing and that unvaccinated individuals remain at risk. The Centers for Disease Control and Prevention (CDC) recommends that children receive their first MMR dose at 12–15 months and a second dose at 4–6 years.

Why This Matters

The deaths underscore the deadly consequences of declining vaccination rates for a disease that was effectively eliminated in the US two decades ago.
Pennsylvania's outbreak of 393 cases across 28 counties shows the rapid spread possible when herd immunity is compromised.
The 2025–2026 measles resurgence is a bellwether for other vaccine-preventable diseases, potentially increasing public health costs and threatening vulnerable populations.

Background

Measles was declared eliminated in the United States in 2000, meaning no continuous transmission for more than 12 months. However, pockets of vaccine hesitancy driven by a debunked 1998 study linking the MMR vaccine to autism (later retracted and thoroughly discredited) have led to outbreaks in under-vaccinated communities. Major outbreaks occurred in 2014–2015 (Disneyland) and 2019 (New York, Washington state). In 2025, the US saw three measles deaths, the first since 2015, and cases surged to a 33-year high. The current Pennsylvania outbreak began in early 2026 and has spread rapidly, with health officials warning that more cases and deaths are likely.

Key Perspectives

Public health officials: Emphasize that the MMR vaccine is safe and effective, and that the only way to prevent further deaths is to achieve high vaccination coverage (95% or more) to maintain herd immunity. They urge parents to vaccinate their children and adults to check their immunization status. Anti-vaccine advocates and groups: Continue to assert that vaccines pose risks that outweigh benefits, often citing unsubstantiated claims about vaccine injury or promoting natural immunity. Some have argued that the 2025–2026 deaths, while tragic, do not justify mandatory vaccination. Epidemiologists and infectious disease experts: Point to growing evidence that vaccine hesitancy, amplified by social media and political figures, is directly responsible for the resurgence. They warn that without stronger public health messaging and policy interventions, the US could see larger outbreaks and more preventable deaths.

What to Watch

The number of new measles cases in Pennsylvania and other states, particularly in communities with low vaccination rates.
Any policy responses from the CDC or HHS under Secretary Kennedy, including potential changes to vaccine recommendations or funding for outbreak response.
School vaccination exemption rates, which have been rising in many states, creating vulnerability for future outbreaks.

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