Two unvaccinated people in Lancaster County, Pennsylvania, have died from measles, health officials confirmed on Tuesday, marking the first measles-related deaths in the United States this year. The state has recorded 393 cases of the highly contagious viral disease in 2026 alone, contributing to a national total of 2,777 confirmed cases — the highest figure in 35 years. Pennsylvania Governor Josh Shapiro described the situation as "a serious and growing problem," stressing that "illness and death from measles is completely preventable."

Officials declined to release further details about the two individuals who died, including whether they were children, who face a higher risk of death and complications from measles. The deaths underscore a troubling gap in vaccination coverage: only 85% of kindergarten-age children in Lancaster County are immunised against measles, well short of the 95% threshold required for herd immunity — the level at which enough people in a population are protected to limit the spread of a disease and shield those who cannot be vaccinated, such as immunocompromised individuals. The US recommends two doses of the MMR (measles, mumps and rubella) vaccine for children between the ages of one and six, a regimen that is 97% effective.

The outbreak arrives against a backdrop of rising vaccine hesitancy and shifting federal policy. Earlier this month, President Donald Trump signed an executive order calling for fewer childhood vaccinations and recommending that the combined MMR vaccine be split into three separate shots. Public health experts have warned the move risks sowing confusion about a safe and well-established vaccine. Health Secretary Robert F. Kennedy Jr., a longstanding vaccine sceptic who has taken steps to revise national vaccine policy, has sent mixed signals on the MMR vaccine — at times endorsing it and at others repeating unproven claims about its safety. Many of his proposed changes to the childhood vaccination schedule were blocked by a federal judge earlier this year.

Governor Shapiro said he spoke directly with Kennedy by telephone on Tuesday and was "very blunt" about the impact of the administration's messaging. "His actions and the rhetoric coming from this administration are having a negative impact on communities across America," Shapiro said, adding that there are "real-life consequences to spreading misinformation." Kennedy offered to deploy staff from the US Centers for Disease Control and Prevention to assist with the outbreak response.

The scale of the crisis is drawing comparisons to recent history. Last year, two unvaccinated children died during a Texas outbreak that infected more than 1,000 people, and the 2025 national total of 2,289 cases was itself a modern record. The US is now on track to lose its official status of having eliminated measles — a designation that reflects sustained absence of endemic transmission — with a review panel set to make that determination in November. Canada lost the same status last year. For a disease that had been declared eliminated in the US in 2000, the current trajectory represents a significant public health reversal.