“It’s a symbolic loss,” said Jennifer Nuzzo, who works at Resolve to Save Lives.
Global health experts meeting in Washington, D.C., are reviewing whether the United States has lost its official measles elimination status after a surge of infections across the country sickened thousands of Americans. The decision by the Pan American Health Organization commission follows outbreaks that have spread across multiple states, bringing the total count to levels not seen in decades.
The Pan American Health Organization commission convened its annual review to determine if continuous measles transmission has persisted for 12 months. The United States held the celebrated distinction of measles elimination since 2000, when PAHO determined the country had interrupted endemic spread. An independent group of experts in epidemiology, public health, virology, pediatrics, and immunization appointed by PAHO examined evidence to assess whether the country had maintained that status.
“You get hit by a semi at 60 miles an hour in an intersection, you pretty much know you've had an accident,” said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota.
Measles Cases and Deaths Reach Highest Levels Since 1991
Centers for Disease Control and Prevention data released in November shows 5,182 confirmed measles cases in the United States so far this year, marking the highest number reported by the agency since 1991. The total more than doubles the 2,289 cases confirmed throughout 2025.
Children and teenagers make up almost 60 percent of confirmed infections, with children under five representing 18 percent and those aged five to 19 accounting for 41 percent.
Federal and state tallies have diverged over mortality figures. While the CDC has recorded four deaths nationally this year, state health departments report eight measles-associated fatalities, including six in Pennsylvania, one in New York, and one in Wisconsin.
The state total includes an infant in Wisconsin who marked the state’s first measles-related death since 1990. State and federal health officials note that nearly 7,500 US measles cases and 11 deaths have been reported since early 2025.
Declining MMR Vaccination Rates Weaken Community Immunity
The resurgence follows a steady decline in routine immunization. Nationwide kindergarten vaccination rates involving two doses of the MMR shot fell from 95.2 percent in the 2019-2020 school year to 92.4 percent for the 2025-2026 school year.
Public health officials emphasize that two doses of the MMR vaccine provide 97 percent protection against infection, requiring high coverage levels to maintain community immunity against the highly contagious virus.
“The only way to prevent infections when there is an ongoing national outbreak at levels that we haven’t seen in decades is to get the MMR vaccine,” said Dr. Andrew Handel, who works as a pediatric infectious diseases physician at Stony Brook Children’s Hospital located in Stony Brook, New York.
Health professionals also stress that individuals with compromised immune systems, pregnant individuals, and young children who cannot receive the vaccine rely on surrounding community immunity for protection against potential complications.
Pennsylvania Leads US Cases as Americas Lose Measles-Free Status
Pennsylvania remains the hardest-hit state, reporting 1,487 confirmed cases. Ohio has recorded 310 cases since January, while Maryland health officials report 67 cases. PAHO’s review follows its November 2025 finding that endemic transmission had re-established in Canada, causing the Americas to lose their regional measles-free designation.
“Loss of measles elimination status in the US signals to the world that we are not up to this task and may diminish their own aspirations to achieve and sustain measles elimination,” said William Moss, a professor at the Johns Hopkins Bloomberg School of Public Health. Experts across public health institutions continue to monitor the transmission dynamics as international health authorities finalize their formal evaluations.
Earlier coverage: The CDC has recorded more than 5,000 measles cases this year