HARRISBURG, Pa. — Pennsylvania health officials on Thursday confirmed a fourth death this year linked to measles in the state, as the outbreak has grown to nearly 700 confirmed cases in 38 counties.
The Pennsylvania Department of Health on Tuesday confirmed two more deaths related to measles. Both were unvaccinated, and one lived in Jefferson County, the other in Mifflin County. The department did not disclose any other identifying information, citing privacy protections.
The latest death comes after two infant deaths in Lancaster County last month. One of those infants, a 6-week-old who died after contracting measles and had a rare genetic disorder, according to local officials. A second infant has died of a ruptured spleen, and local officials say measles contributed to the death.
Pennsylvania had 693 confirmed measles cases in 38 counties as of Sept. 14, up from 676 cases in 37 counties three days earlier. State officials have described the outbreak as an ongoing public-health emergency requiring continued surveillance and vaccination activities.
The outbreak has also underscored a broader decline in measles vaccination rates in the United States. According to CDC data, MMR coverage among U.S. kindergartners decreased from 95.2% in the 2019–20 school year to 92.4% in 2025–26. The CDC says it usually takes vaccination coverage greater than 95 percent to maintain strong community protection against measles.
The United States declared measles eliminated in 2000, meaning there was no longer sustained transmission of the virus. Elimination does not mean that the virus has been eradicated; imported cases from infected travelers can still occur, and transmission can still happen in communities with low vaccination coverage.
The current outbreak has also revealed a split between Pennsylvania officials and the federal government over the classification of some deaths.
Pennsylvania health officials said they consulted local coroners to investigate the deaths before concluding they were measles-related. The department said the investigations included evidence of measles infection, laboratory testing, and an assessment that the deaths were from a related condition.
The CDC, meanwhile, has stated its national death toll relies on a different reporting and review process. The agency said in its Sept. 10 update that the National Center for Health Statistics has no death records from 2026 listing measles as the underlying cause. CDC, in collaboration with the Council of State and Territorial Epidemiologists, is developing a standard case definition for reporting deaths from measles.
That distinction doesn’t mean state and federal officials are reporting different infections. Instead, it is a result of different review and classification processes for mortality data.
Measles is highly contagious and can lead to serious complications such as pneumonia, encephalitis, and, in some cases, death. Some groups can be particularly vulnerable. One such group is infants too young to receive routine vaccination. The first dose of the MMR vaccine is recommended between 12 and 15 months of age.
The Pennsylvania Department of Health continues to update confirmed cases, hospitalizations, deaths, and vaccination efforts as the outbreak unfolds. The department also warned of a possible measles exposure in Mifflin County on Sept. 14, where one person tested positive for the virus.
The U.S. also faces a review of its measles-elimination status in 2026. CDC guidance defines elimination as the absence of sustained measles transmission for at least 12 months.
