Measles complications hospitalised over 150 people and killed three, including two children.
The United States has reached its highest annual measles case tally in 33 years, hitting at least 1277 confirmed cases across 38 states and the District of Columbia.
The milestone marks a public health reversal in defeating a highly contagious, vaccine-preventable disease as the anti-vaccine movement gains strength.
The nation surpassed infections reported in 2019, reaching the largest number of cases since 1992, when officials recorded more than 2100 infections, according to data published by the Johns Hopkins University Centre for Outbreak Response Innovation (CORI).
“It’s devastating,” said Claire Hannan, executive director of the Association of Immunisation Managers, a national organisation of state and local immunisation officials. “We worked so hard to eliminate the threat of measles and to keep it at bay.”
Authorities said at least 155 people have been hospitalised and three people have died of measles-related complications this year. The dead include two otherwise healthy children in Texas and a man in New Mexico, all of whom were unvaccinated. In contrast, only three measles deaths were reported between 2001 and 2024, according to the Centers for Disease Control and Prevention.
About 92% of measles cases in 2025 were in people who were either unvaccinated or whose vaccination status was unknown, according to the CDC.
Data from the CDC does not yet reflect the record as it is updated weekly on Wednesdays, while the Johns Hopkins’ site validates data every weekday.
The largest outbreak has been in West Texas, where officials have recorded more than 750 cases since late January and believe the true toll is much higher. Data shows that outbreak has slowed, but that it has spread to surrounding states.
Unrelated clusters of cases emerged elsewhere, usually originating with an unvaccinated person who travelled abroad.
Measles was officially eliminated from the US in 2000 with high vaccination coverage and rapid outbreak response. Cases still popped up periodically. But in recent years, large outbreaks with 50 or more cases have become more frequent, especially in close-knit communities with low vaccination coverage.
Public health experts say the US is on track to lose the elimination status if there is continuous spread of linked measles cases for more than 12 months.
“It’s a harbinger of things to come,” said Eric Ball, a pediatrician who heads the California chapter of the American Academy of Pediatrics. “Once we see a resurgence of measles, we know that other diseases are going to come behind it.”
Misinformation about the safety and effectiveness of the measles, mumps and rubella vaccine fuelled the 1274 cases recorded in 2019, according to public health officials and researchers.
The outbreaks that year were concentrated in ultra-Orthodox Jewish communities in New York, highlighting the risks in tight-knit communities where vaccine distrust takes hold.
Confidence in public health measures, especially vaccines, has fallen since then, and is sharply divided along political lines.
The national rate for MMR vaccination among kindergarteners was slightly above 95% in 2019, the level of community protection scientists say is needed to prevent measles outbreaks. But that rate is now under 93% and falling, according to the CDC.
Even in states with high vaccination coverage, pockets of unvaccinated people tend to cluster together. Measles is so contagious that a person without immunity exposed to the virus is highly likely to be infected and to spread it days before they develop symptoms.
A recent study showed that if US vaccination rates continue to decline, the nation could face millions of cases over the next 25 years.
A poll conducted in March by the Harvard TH Chan School of Public Health and the de Beaumont Foundation found that 79% of adults say parents should be required to have children vaccinated against preventable diseases such as measles, mumps and rubella to attend school. Support was stronger among Democrats, 90%, than among Republicans, 68%.
Five years after the start of the coronavirus pandemic, less than half the public says it has at least some confidence in federal health agencies to carry out core public health responsibilities, according to a poll conducted in April by the health care think tank KFF.
Health and Human Services Secretary Robert F Kennedy Jr, a longtime anti-vaccine activist who ascended to be the top US health official, has offered mixed messages about measles and the vaccine to prevent it.
He initially downplayed the seriousness of the Texas outbreak after the first child died, saying: “We have measles outbreaks every year.” He accompanied his calls for vaccination with caveats, raising concerns about the shots that public health experts called unfounded.
Nola Jean Ernest, a paediatrician in rural southeastern Alabama, said many of her patients trust others who share their political views more than her when it comes to vaccination.
She now sees patients who vaccinated older children refuse to vaccinate their infants.
“I’ve had several conversations in the last few months where they will say, ‘We still trust you, we just don’t trust the vaccines,’” Ernest said recently. “That really breaks my heart.”
In Texas, infections in late January spread quickly within Gaines County’s Mennonite community, some of whom educate their children at home or at private schools without vaccine mandates. The county had among the lowest kindergarten MMR vaccination rates in Texas, about 82%, according to state immunisation data.
Public health officials said they faced challenges in controlling the outbreak because many people were not getting tested or vaccinated for measles.
Anti-vaccine groups mobilised quickly on the ground. Many Mennonite families turned to a prominent anti-vaccine doctor who offered unproven alternative treatments. Kennedy praised that doctor and his methods in a visit to the region.
Children’s Health Defense, an anti-vaccine group founded by Kennedy, interviewed the parents of a 6-year-old girl who died of measles, blaming her death on medical error rather than vaccination status. The organisation did not immediately return a request for comment.
Eventually, 36 Texas counties reported measles cases.
Young adults from El Paso who work in oil fields close to Gaines County were among those infected this spring.
El Paso went from five cases to 53 in a month, said Hector Ocaranza, director of the city and county health authority. Ocaranza said his community was vulnerable because a growing number of young adults, listening to what they see and hear on social media, are not getting vaccinated.
Lara Anton, a spokeswoman for the Texas Health Department, said last week that the reporting of new measles cases has slowed, crediting rising population immunity from infections and increased vaccination.
But the outbreak is not over.
Transmission is continuing in Gaines County, as well as Lamar County, in northeast Texas bordering Oklahoma, according to health department data.
In Chihuahua, Mexico, which borders Texas and New Mexico, a child who visited Texas in February started a large measles outbreak that now exceeds 2400 cases and eight deaths as of last week, according to data from the Pan American Health Organisation.
Measles outbreaks require vast personnel, time, dollars and messaging, public health experts say.
The 2019 outbreak cost New York City $8.4 million with 550 staff involved in the response, according to a 2020 report in the New England Journal of Medicine.
Funding for state and local public health agencies, including immunisation programmes, has been slashed after increasing during the pandemic. Public health workers have been laid off because of widespread budget cuts across the federal health agencies.
Because of the decreased funding, Texas had to pull resources and staff from other parts of its health department to respond to the outbreak, David Sugerman, a senior CDC scientist, told a committee of agency vaccine advisers in April.
In Dallas, which has had one measles case this year, health officials had to lay off 16 immunisation staff because of federal cuts, said Philip Huang, director of the county’s health and human services department.
“The fact that this is occurring at the same time that we are seeing more measles cases in Texas than we have seen in more than 30 years makes absolutely no sense,” Huang said.