An infant is one of the 2 measles-associated deaths in Pennsylvania
An infant was among the two "measles-associated deaths" in Pennsylvania, the state health department confirmed to ABC News on Wednesday.
Both individuals from Lancaster County were unvaccinated.
The health department said they classify a death as "measles associated" when there is evidence of measles, either through laboratory testing or epidemiological links. The specific cause of death will be determined by the county coroner, whose investigation into the infant’s death is ongoing.
ABC News reached out to the county coroner for additional details but did not immediately hear back.
The two individuals mark the first deaths related to measles within the state in 35 years, according to the Pennsylvania Department of Health, and the first deaths reported this year in the U.S.
"My deepest sympathies are with the loved ones who are facing this unimaginable loss," Dr. Debra Bogen, the state's secretary of health, said in a statement. "Because measles was largely eliminated in the Commonwealth for more than three decades, people are not familiar with this disease and don't fully understand the potential severity of the illness."
To protect the privacy of the patients and their families, the health department said it will not release any additional details that could lead to the identification of the individuals.
In late July, the number of confirmed measles cases in the U.S. surpassed the total reported for all of last year, according to data from the Centers for Disease Control and Prevention.
Last year's total of 2,289 was previously the highest number of recorded measles cases in more than 30 years, CDC data shows. However, the 2,777 total now marks the highest number of cases recorded since 1991.
The CDC currently recommends that people receive two doses of the measles, mumps, rubella (MMR) vaccine, the first at ages 12 to 15 months and the second between 4 and 6 years old. One dose is 93% effective and two doses are 97% effective against measles, the CDC says.
However, CDC data shows vaccination rates have been lagging in recent years. During the 2025 to 2026 school year, 92.4% of kindergartners received the MMR vaccine, according to data. This marks the third straight school year with declining MMR coverage rates and is lower the 95.2% seen in the 2019 to 2020 school year, prior to the COVID-19 pandemic.
"We want to ensure every Pennsylvanian has the information they need to protect themselves, their loved ones and their communities," Bogen's statement continued. "As a physician, I want to make sure that people understand that the MMR vaccine is safe and provides the best protection we have against measles."
Pennsylvania is experiencing its largest measles outbreak since 1992, according to Gov. Josh Shapiro. As of Aug. 26, the state has reported more than 420 measles cases across 30 counties this year, with 94 of those cases reported in the last seven days. Nearly 20% of cases have been hospitalized.
The bulk of cases have been reported in Lancaster County. Geisinger Medical Center in Danville said it was responding to a potential measles exposure from a visitor in its neonatal intensive care unit on Friday.
The hospital said the visitor was present on the hospital's campus from 5 p.m. ET on Friday, Aug. 14, to 6:30 p.m. ET on Monday, Aug. 17, and later tested positive for the virus. The individual reportedly only visited the NICU and Ronald McDonald House in Danville during that timeframe.
ABC News' Dr. Jade Cobern contributed to this report.
