Updated October 15, 2025 at 12:55 PM EDT
Nearly two months after a deadly, massive measles outbreak in Texas was the highly contagious disease continues to spread across the country. The U.S. has now confirmed this year, according to the Centers for Disease Control and Prevention — the highest annual number .
But the true total could be even higher, says , director of the Vaccine Education Center at the Children's Hospital of Philadelphia.
"If you talk to people on the ground, including not only in Texas, but other states, they all say the same thing, which is that the numbers are much worse than that. Probably closer to 5,000 cases," Offit says. "And it's not done."
He points to the current outbreak in South Carolina, where 139 schoolchildren at two schools are now subject to a 21-day quarantine after being exposed to measles. The state Department of Public Health on Tuesday case since July, including 12 cases directly linked to an ongoing outbreak in Spartanburg County.
"There is active, unrecognized community transmission of measles occurring," , South Carolina's state epidemiologist, told reporters during a last week. She said that makes it vital that the public receive the recommended measles vaccination.
Meanwhile, a large measles outbreak along the border areas of Arizona and southwestern Utah continues to grow, with Utah now this year as of Tuesday. Nearly all of the cases occurred in people who were unvaccinated. Six people required hospitalization. According to the Utah Department of Health and Human Services, wastewater testing shows that the measles virus is more widespread in the state than previously known.
In neighboring Arizona, officials have reported so far this year as of Tuesday — including 14 new cases since last week.
And in Minnesota, officials last week reported that a small, recent surge in measles cases there has brought the state's .
All told, the CDC 44 measles outbreaks in 41 states this year. The agency defines an outbreak as three or more cases that are linked. The vast majority of cases were in people who were unvaccinated; 27% percent have been in children under the age of 5. About 1 in 8 measles cases have resulted in hospitalization.
Widespread vaccination in the U.S. has saved hundreds of lives each year
Measles is one of the most known to humans. On average, an infected person will infect as many as 18 other unvaccinated people. A person with measles can emit infectious particles that linger in the air for up to two hours, long after they've left a room. That's why it's so highly transmissible.
Before widespread vaccination, pretty much everyone got measles in childhood. And 400-500 people in the U.S. used to die from it each year.
The disease was declared eliminated in the U.S. in 2000. To protect communities against outbreaks, they need a vaccination rate of 95%, according to the CDC.
Nationwide, measles vaccination rates have been slipping for years — . The trend predates the current administration, but Dr. Adam Ratner, a pediatric infectious disease specialist in New York City, says it doesn't help that Health Secretary Robert F. Kennedy Jr. has a long history of criticizing vaccines. Ratner notes that acting CDC Director Jim O'Neill has suggested breaking up the standard measles, mumps and rubella vaccine , which Ratner says is neither feasible nor is it backed by evidence.
In a statement to NPR on Tuesday, Health and Human Services spokesperson Andrew Nixon said, "Secretary Kennedy is not anti-vaccine — he is pro-safety, pro-transparency, and pro-accountability," and wants to ensure that vaccines "are backed by gold standard science." He added, "Secretary Kennedy has been outspoken in his support for the measles vaccine."
Kennedy earlier this year. But senators from both parties have with his approach to vaccine policy.
"It's no wonder that parents are, you know, confused and frightened," says Ratner, the author of Booster Shots, a history of the fight against measles and its recent resurgence.
In some communities, kindergarten vaccination rates are much lower than the national average. That's created pockets of opportunity for measles to spread, Ratner says.
"If a measles case comes into a place with a low vaccination rate, it can really take off," Ratner says. "That's what we saw in Gaines County" — the epicenter of the Texas outbreak that saw — "and that's what we're seeing in lots of places."
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