Utah’s measles outbreak has slowed, but the start of school and colder weather in the fall may create another surge. ‘It’s still transmitting’

Utah has spent the past year fighting measles outbreaks — a grim milestone that could affect whether the United States can keep its measles-free designation.

More than 680 people have gotten sick since the state’s first outbreak began on June 20, 2025.

Unlike measles outbreaks in Texas, South Carolina and Arizona, the spread in Utah has been tough to contain to one region — infecting undervaccinated communities in nearly every county.

Measles popped up in healthcare settings, big-box stores and restaurants, and youth sporting events. In February, an exposure at a state high school wrestling championship sparked at least 46 cases among attendees.

Measles is one of the most contagious diseases known to medicine. It causes a tell-tale rash, high fevers, strong cough, ear infections and diarrhea.

While most recover, some — including young babies, pregnant people and those with weak immune systems — are at higher risk of developing dangerous complications like pneumonia, brain swelling, blindness or even dying. Even healthy people can develop issues years down the road, including a rare but fatal degenerative brain disease that manifests about a decade after infection.

The measles vaccine is safe and 97% protective after two doses.

Though Utah’s spread has slowed in recent weeks, state epidemiologist Leisha Nolen sees little opportunity to rest. She’s worried the start of school and arrival of colder weather in the fall will cause measles to surge again.

“It’s still here, it’s still transmitting,” she said. “We just need those few cases to hit the wrong community and it could flare up really big again.”

Utah sees the impacts of dropping vaccination rates

The worst spread has been in the southwestern part of the state, where 265 people have fallen ill with the vaccine-preventable disease since last summer. Overall, measles infections hit 22 of the state’s 29 counties.

In the state’s rural northeast, the conditions were also ripe for measles to spread. Daggett, Duchesne and Uintah counties — collectively dubbed the “tricounty” health region — has seen the second-largest decline in childhood vaccination rates in the state.

More than 16% of the region’s kindergarteners were missing their measles vaccines in the last school year, according to state data. Statewide, 12.8% were missing their vaccine, putting the state far short of the 95% vaccination rate needed to prevent measles outbreaks.

The TriCounty Health Department logged 74 cases of measles this spring, after people who got sick at the youth wrestling tournament spread the virus in school and later within their households.

The frontier region had seen a rise in vaccine hesitancy for some time, said Sydnee Lyons, the health department’s public information officer.

Despite the large number of cases, local and state health officials consider TriCounty’s measles response a success.

Health officials focused efforts on mitigating the inevitable spread. Unvaccinated students were excluded from in-person school and people who were sick were told to isolate themselves. And their appeal to care for one’s neighbors led to more people coming in to get vaccinated, officials said.

TriCounty’s infectious disease specialist Cyndie Mattinson recalled a parent who told a school nurse she didn’t want to talk to the health department because “she was worried that we would be angry with her and be judgmental because her children were unvaccinated.”

The nurse vouched for the health department staff, and told the mom to let her know if she felt judged. Mattinson ultimately had a great conversation with the mother.

“The perceptions were changed that we weren’t out there to police, we were there to be a help and a resource to the community,” Mattinson said.

Health experts will meet to decide on US measles status

Utah’s lengthy battle with measles will likely affect whether the U.S. can keep its measles-free designation. Public health officials consider measles to be eliminated from a country when it shows it stopped continuous spread within local communities for at least a year.

The national measles case count was 2,104 as of June 18, nearly surpassing last year’s record total.

Utah has fought measles for a year, but it’s not clear if the earliest clusters are connected with the major outbreak on the Utah-Arizona state line, which was detected in August, Nolen said.

But since then, most of the state’s measles cases have come from within Utah, not from other parts of the country.

International health experts will gather in November to determine if the U.S. and Mexico have lost their measles elimination status. Canada lost its status last year after ongoing outbreaks.

In Utah, doctors continue to reassure scared patients and lobby for better public health policy.

Dr. Ellie Brownstein, president-elect of the state chapter of the American Academy of Pediatrics and a pediatrician in Salt Lake City, spent the height of the outbreak opposing a bill that would have made school vaccine waivers easier to get. It failed, but she says there hasn’t been a clear cultural reckoning over measles’ resurgence.

“I don’t know that we get it to end,” Brownstein said. “I don’t know that we’re going to get this genie back in the box because there’s enough people out there to spread it.”

This story was originally featured on Fortune.com