As of 27 September 2026, the cumulative number of confirmed cases of measles in Pennsylvania had exceeded 900, with 13 new infections on that date, the worst measles outbreak in the state since 1991, which has now caused the deaths of four unvaccinated residents, and the first measles-related deaths in 35 years in Pennsylvania, with Amish communities in Lancaster County at the heart of the epidemic. According to various media reports, the Governor of Pennsylvania, Josh Shapiro, has convened public health conferences on the epidemic, calling for greater control by the state health sector to prevent further spread of the epidemic.
This measles outbreak has continued to climb rapidly since its occurrence in the south-east of Pennsylvania in the summer of 2026. Official data indicate that, by mid-September, cumulative cases in the counties had surpassed 800 cases, with a maximum of 43 new infections per week, and that the rate of increase has continued to rise since then, albeit at a slow pace, until 900. At present, all deaths are of residents who have not been vaccinated against measles, many of them from the Amish mass area of Lancaster County, where the community ' s low acceptance of routine vaccination due to religious and cultural traditions is the core point of the epidemic ' s spread. The United States Centers for Disease Control has listed Pennsylvania as a high-risk area for measles in the country and has advised residents to avoid unnecessary access to the worst affected areas.
The early cases of the epidemic dated back to June 2026 and first appeared in the Amish community in Lancaster County, where the virus quickly spread within the community due to the high mobility and low vaccination rates, and then spread to surrounding districts and municipalities. Since July, the state health sector began to publish weekly epidemic data, the number of cases rose rapidly from the initial digits to 600 in mid-August, breaking 800 at the beginning of September, and the latest report of 27 September shows that there were 904 cumulative cases, with 13 new cases added that day and 4 cumulative deaths. Measles are acute respiratory infections caused by the measles virus, transmitted through air foam, extremely contagious, with up to 90 per cent of unvaccinated populations affected by the infection, common complications including pneumonia, mesopitis and encephalitis, which can lead to death in serious cases, and the risk of miscarriage or premature birth as a result of infection by pregnant women.
The first group directly affected by the epidemic is the population that has not been vaccinated against measles, particularly in the Amish community, which is the worst affected area of the epidemic; the second group is children who have not completed two doses of measles vaccination, and those who have not completed a full course of vaccination are at a much higher risk of severe disease than those who have been vaccinated; the third group is people with immuno-deficiency, such as cancer patients undergoing chemotherapy and patients who use immunosuppressants after organ transplants, who may be infected with insufficient immuno-response and risk of death after infection; and the fourth group that has recently travelled to areas severely affected by the epidemic, such as Lancaster County. Health authorities in Pennsylvania have now organized medical personnel into the Amish community to conduct house-to-house vaccinations and health awareness campaigns, as well as the creation of temporary vaccination sites in areas severely affected by the epidemic and the provision of free vaccines to uninoccupied populations.
The spread of the epidemic has also given rise to public health policy controversy. It has been reported that over 10,000 negative public comments were received as a result of a previously proposed regulation of disease tracking and vaccination by the Pennsylvania Government, which, in mid-September, announced the withdrawal of the regulation, stating that it would be resubmitted with the full inclusion of public comments, as a result of compulsory controls that would violate privacy and restart the epidemic. At the same time, the United States Secretary of Health and Human Services, Robert Kennedy Jr., publicly questioned the official Penn State findings of measles-related deaths, stating that the deaths of two Lancaster County infants were not measles, which provoked widespread criticism from the public health community. Shapiro publicly refuted that the decision on the cause of death in the state health sector had been made by a team of clinical experts with a clear medical test, accusing the public of false statements that would mislead the population and increase the risk of infection among the unvaccinated population. The White House, for its part, has also expressed its support for disease prevention and control measures in Pennsylvania and has called on the public to complete vaccinations as soon as possible, based on official information.
Measles is now classified as a mandatory reported infectious disease in the Pennsylvania health sector, and all medical institutions must report suspected cases at first sight. Officially, the rate of increase in cases is expected to slow down over the next two to four weeks as community vaccination rates rise, but low vaccination rates in the Amish community due to cultural traditions may take longer to control the spread of the epidemic. For the general population, first, it is necessary to confirm its own measles vaccination history and, if two doses are not completed, to visit local health clinics, a chain of dispensaries or designated points of vaccination as soon as possible, with 97 per cent of the post-inoculation protection effectiveness; second, if there are suspected measles symptoms, such as fever, rashes, coughs, meningitis, etc., it should immediately be taken under a mask to avoid contact with unvaccinated children and people with immuno-deficiency disorders; and third, it should be avoided in the near future to areas affected by the epidemic, such as Lancaster County, where vaccination must be completed earlier. The state health sector will update the epidemic data on a weekly basis through the official network, and the public will be able to consult the latest developments.