As of the CDC's update on Friday, the U.S. has confirmed 4,588 measles cases this year across 47 jurisdictions and 42 new outbreaks, compared to 2025's total of 2,289 confirmed cases.
Though the CDC has recognized three measles deaths this year, Pennsylvania alone has reported five. Local authorities reported a sixth death, but it’s currently under investigation.
The state reported 1,338 cases across 44 counties — nearly 30 percent of the nationwide total.
The CDC reports that 96 percent of cases occurred among people who were unvaccinated or had unknown immunization statuses. The majority of infections, 59 percent, have occurred among people aged 19 and younger.
While official numbers indicate nearly 7,000 cases have been recorded since the start of 2025, when measles transmission began worsening, infectious disease experts speculate that a significant portion of cases have gone underreported.
Andy Pavia, pediatric infectious disease epidemiologist at the University of Utah, said at the annual IDWeek infectious disease conference this week that the true total since last year is “probably greater than 20,000.”
“We're up against enormous odds,” said Pavia. “Our politicians are waging warfare and lawfare against public health, against vaccines, against science, and against essentially our patients' best interests.”
While federal leadership has given soft, tacit support for the measles, mumps and rubella (MMR) vaccine, members of the Trump administration have also continued to cast doubt on the safety of the shot.
Earlier this year, President Trump signed an executive to split up the doses of the MMR vaccine, claiming without evidence that the combined vaccine that's been around since 1971 can be “quite lethal."
