Pennsylvania is reporting 74 new measles cases since Monday, the state's health department said Wednesday.
A total of 1,078 cases have been reported in the state so far this year. At least 207 people have been hospitalized and five people have died, according to the Pennsylvania Department of Health (DOH).
"Of the 74 cases added, more than 40 represent individuals who were sick more than two weeks ago and are no longer contagious, but their cases were only recently reported and subsequently confirmed, the DOH said. Wednesday's update "does not reflect a current surge in new infections."
Of the five people who died, two of the deaths were among unvaccinated adults: an 18-year-old and a 40-year-old. The other two deaths were among infants who were too young to have received the measles, mumps, rubella (MMR) vaccine.
The fifth death occurred in an unvaccinated resident of Lancaster County, in southeastern Pennsylvania, but it is unclear how old the individual is. Lancaster County is the epicenter of the state's outbreak, with 401 cases confirmed so far.
One-third of cases are among those under 18 years old and fewer than 1% of cases are among those fully vaccinated with the MMR shot, according to DOH data.
The Centers for Disease Control and Prevention recommends that people receive two doses of the MMR vaccine, the first at ages 12 to 15 months and the second between 4 and 6 years old. One dose is 93% effective in preventing measles infection and two doses are 97% effective, the CDC says.
Infants aged 6 to 11 months living in or traveling to high-risk outbreak areas may receive an early third dose of the MMR vaccine.
CDC data, however shows vaccination rates have been lagging in recent years. During the 2025-26 school year, 92.4% of kindergartners received the MMR vaccine, according to data. This is lower than the 95.2% seen in the 2019-20 school year, prior to the COVID-19 pandemic.
"State health center staff have administered more than 5,700 MMR vaccinations at 198 pop-up vaccination clinics in the affected communities since the outbreak began in late April," DOH wrote in a press release on Wednesday.
"Dozens of additional vaccine clinics are scheduled for the upcoming weeks and months, based on community interest and need," the press release continued. "In pop-up clinics and at state health centers combined, Department nurses have administered nearly 9,000 MMR vaccine doses to residents across the Commonwealth in 2026."