Measles is an old scourge that’s rapidly re-emerging as a new one. According to numbers released by the U.S. Centers for Disease Control and Prevention (CDC) on July 24, there have been 2,318 cases of measles reported nationwide so far in this year, already exceeding the 2,289 cases reported in all of 2025. The current figure is the highest incidence of measles in 35 years, a record set back in 1991 when there were 9,643 U.S. cases
It wasn’t long ago that measles cases were extremely rare in the U.S. In 1963, the first measles vaccine was introduced in the U.S., and decades of steady administration of the shot eventually led to the country being declared measles-free in 2000. There were some scattered infections in the ensuing years—56 cases in 2003, 55 in 2012, 13 in 2020. But this year and last year, the numbers have exploded
The surge has come amid a backdrop of drastic changes to childhood vaccinations. In January 2026, the CDC changed the childhood vaccine schedule—despite experts and organizations saying there had been no change in the science—after President Donald Trump directed the agency and Robert F. Kennedy Jr., Secretary of Health and Human Services and a longtime vaccine skeptic, to review how other developed countries issue vaccine recommendations. The new guidelines reduced the number of recommended vaccines for children from 17 to 11. Though the measles vaccine is still on the “recommended” list, recent research published in Science showed that changes in the CDC’s vaccine messaging under the Trump Administration reduced the public’s trust in the agency and in vaccines, while increasing perceptions that vaccines are not safe.
Even before the second Trump Administration, vaccination rates for measles nationwide were down. Generally, it takes 95% vaccination coverage for a population to achieve what is known as herd immunity, the protection that is afforded when there are so many people inoculated against a disease that the pathogen can’t gain an infectious toehold in a society and reach that small part of the unvaccinated population—generally those who are too young to be vaccinated or those who cannot receive the shots for medical reasons such as compromised immune systems. Vaccination rates are not available for the 2025-2026 school year yet, but for 2024-2025 the number was just 92.5%, down from 95.2% in 2019-2020.
That much of a drop in vaccination coverage creates pockets for viruses, like the one that causes measles, to spread. Of measles cases so far in 2026 and for the entirety of last year, 93% have been among unvaccinated children, 3% were among children who received just one vaccine dose, and 4% were among kids who received both. This year, 7% of those cases resulted in hospitalizations. There have been no deaths so far this year, but there were three in 2025—one of them an unvaccinated adult, and two of them children with no known underlying health conditions.
“There were two healthy little girls in West Texas that died from measles,” said Dr. Paul Offit, Director of the Vaccine Education Center at the Children’s Hospital of Philadelphia, in an email to TIME. “Those were the first measles deaths in a child in this country in more than 20 years. I think it is fair to say that measles is epidemic in the United States. And if people are coming from outside this country to the United States, they better make sure they’re up-to-date on their immunizations.”
Adds Dr. Peter Hotez, Dean of the National School of Tropical Medicine at the Baylor College of Medicine: “For all practical purposes measles has returned to the United States, both in terms of cases and hospitalizations, as well as two needless deaths. We should expect our annual winter-spring surges of measles to get even worse in subsequent years. And it won’t be just measles—pertussis is also returning, and other childhood infectious diseases might follow.”
