The measles outbreak in South Carolina now stands at 664 cases, more than doubling in a few weeks, officials said this week. The highly contagious virus has also spread onward to North Carolina, Ohio and Washington state, and similar outbreaks are unfurling in Arizona and Utah as well.
The outbreak, which first began in Texas a year ago this week, has spread to most US states – and as the US passes the one-year mark, its measles-elimination status will probably end, a symbol indicating an expected wave of year-round preventable disease. The outbreak has been plagued by misinformation, with Robert F Kennedy Jr, secretary of the US Department of Health and Human Services and longtime vaccine critic, framing measles vaccination as a personal choice and promoting unproven treatments.
The vast majority of those infected are children, and most of them did not receive the measles, mumps, and rubella (MMR vaccine). Last year, there were 2,242 confirmed cases of measles across 44 states, according to the US Centers for Disease Control and Prevention (CDC). There have already been 171 measles cases reported in nine states in 2026 – and that number does not include the jump in cases reported by South Carolina on Friday.
“I think it’s just the new normal, unfortunately, that public health departments have to be responding to,” said Katherine Wells, director of public health in Lubbock, who oversaw the city’s response to the west Texas measles cluster.
In 2026, measles will probably percolate in more communities with low vaccination rates and then put pressure on vulnerable children and adults even in highly vaccinated communities, she said. And measles isn’t the only fear.
“Measles is the canary in the coalmine,” Wells said. “As we see lower and lower vaccination rates, we could see an outbreak of rubella or polio or some of these other vaccine-preventable diseases.”
Because it is so highly contagious – it can linger in the air in a room for two hours – measles typically spreads more quickly than other infectious diseases. But preventable illnesses like polio, tetanus, diphtheria and whooping cough are not far behind a measles outbreak.
“Measles is a bellwether,” said James Alwine, emeritus professor at the University of Pennsylvania, a virologist, and a member of the coordinating committee of Defend Public Health. “It means that your vaccination level is so low that all the other vaccine-preventable diseases will come up with time.”
Vaccination rates are falling throughout the US as exemptions from school mandates increase, according to new research published in the Journal of the American Medical Association (Jama). Kennedy has been a “key figure” in growing anti-vaccine sentiment for decades, “denigrating vaccines in general, specifically the MMR vaccine, trying to link it with autism when there’s no link”, said Rob Davidson, an emergency physician in western Michigan and executive director of the Committee to Protect Health Care – adding that the danger had increased now Kennedy has “the largest megaphone of public health in the country, maybe in the world”.
Davidson has been a doctor for 28 years, and like many of his peers, he has never seen a case of measles – all because of vaccines, he said. Now, he is preparing for the day he might encounter the disease in a patient.
“This is something we have to be thinking about on a regular basis again,” he said. “It is a gut punch. It didn’t have to be this way.”
In South Carolina, 531 people are currently in quarantine and 85 in isolation, and eight people have been hospitalized with measles since the start of the outbreak.
“We feel like we’re really kind of staring over the edge, knowing that this is about to get a lot worse,” Johnathon Elkes, an emergency medicine physician at Prisma Health in Greenville, South Carolina, said on Friday.
Helmut Albrecht, an infectious disease specialist at Prisma Health, pleaded with the public on Friday to get vaccinated: “We have right now the largest outbreak in the US, and it’s going to get worse before it gets better.”
In North Carolina, seven out of eight cases reported in recent weeks were linked to the South Carolina outbreak. At least three children each in Ohio and Washington have also been sickened in the spiraling outbreak, which was first detected in Texas nearly a year ago. The virus is spreading in other states as well. Arizona has seen 217 cases and nine hospitalizations in this outbreak, which started for them in August, and Utah has had 210 cases since its first case was detected in June.
The Pan American Health Organization (Paho) on Friday said it planned to review in April the measles elimination status of the US and Mexico given the ongoing outbreak.
The outbreak began a year ago, on 20 January 2025, when the first child in Texas who tested positive for measles developed a rash. When Wells heard that two children had tested positive and needed to be hospitalized, she feared, correctly, that it was the tip of the iceberg, since one in five children with measles need to be hospitalized.
“Our investigation revealed that there were many, many, many sick children with measles on the ground,” Wells said. “We were already in a full-blown outbreak.”
The Texas cluster officially ended in August after 762 confirmed cases, 99 hospitalizations, and the deaths of two young children. But by then, the outbreak had already widened to other states.
Losing the US measles elimination status is a warning, Wells said: “We’re now entering an era where we’re going to see outbreaks in these unvaccinated communities, and then I think those outbreaks will start putting pressure on other, more-vaccinated communities.”
Children under the age of one or with health conditions are the most vulnerable even in highly vaccinated communities. It is a particular concern in healthcare settings, where a child undergoing cancer treatment might come into contact with a measles patient – especially because the early symptoms of measles are a cough and runny nose; the telltale rash only sets in later.
During the Texas outbreak, Lubbock public health gave out thousands more MMR vaccines than usual, and other areas of the state also mobilized a response, with pharmacies seeing a surge in demand.
Some parents in Lubbock vaccinated their infants early – babies over the age of six months can get the shot early, as long as they receive a third shot later, and while the second dose is usually recommended at age four, young children can receive it earlier. School nurses reached out to the families of students who were behind on vaccinations or who had opted out for non-medical reasons, letting them know about the safety and importance of vaccines.
“We had parents come into our clinics who had never vaccinated their children, but seeing the disease and hearing about it on the news, they said: ‘Oh, this is real. Let me get my child vaccinated,’” Wells said.
But experts are worried by the recent announcement that the US will no longer fully recommend several important vaccines in childhood, which could create access issues and further confusion.
“Putting them on a non-recommended list is going to make people think that maybe they’re not important, maybe they’re not needed,” Alwine said. School mandates are also coming under fire by anti-vaccine advocates, particularly now that several recommendations have changed.
“We need to make sure that vaccines are available and that individuals know how life-saving vaccines can be,” Wells said. “The majority of parents from both political sides believe in vaccines and want to see kids being vaccinated. And we need to make sure that those parents, and people who would really be impacted if those vaccination rates start dropping in schools, really speak out and speak up about [how] it’s important that we keep kids vaccinated.”
The resurgence of preventable illness is straining an already overburdened health system.
“Undoubtedly we’re going to see more meningitis, hepatitis, RSV, rotavirus – all the things that they just took off the [full] recommendation list,” said Davidson. The thought of seeing more illness was “gutting”, he said.
Local public health departments all over the country are now preparing for their own cases of measles and other threats. One of Wells’s top pieces of advice is improving ties with the community.
“We need to have more boots on the ground, working with communities, for all different types of health outcomes and health concerns,” she said. Those efforts can go a long way in identifying cases before they explode into an outbreak – and they can result in important conversations about why these diseases are such a threat.
“We’ve lived in the golden age of medicine for so long that there are so many people who have never seen these diseases, don’t even think about them, don’t even know they exist any more,” Alwine said. “Or people think they’ve been eliminated, but they’re not. They’re just waiting.”
