The measles outbreak in South Carolina is showing little sign of slowing down. The state has confirmed 847 cases since the first case was reported in October, making the outbreak bigger than the one in Texas, which started just over a year ago.
Dr. Linda Bell, South Carolina's state epidemiologist, points out that in Texas, measles cases grew over the course of seven months, while in South Carolina it has taken just 16 weeks to surpass the Texas case count.
"This is a milestone that we have reached in a relatively short period of time, very unfortunately," she said at a press briefing Wednesday. "And it's just disconcerting to consider what our final trajectory will look like for measles in South Carolina."
The state on Friday reported 58 new cases since Tuesday.
This latest outbreak, as well as the speed at which it is spreading, is another test of the United States' ability to contain measles. It comes as the Trump administration has taken multiple steps to undermine overall confidence in vaccines.
And it is happening as the U.S. is already in danger of losing its status as a country that has eliminated measles. That's a technical designation. It's given to countries that have gone a year without a continuous chain of transmission. For the U.S., the clock started in January 2025 with the Texas outbreak.
Who makes the call?
Measles elimination status is granted — and taken away — by a special verification commission set up by the Pan American Health Organization (PAHO). It reviews extensive evidence to determine whether the outbreaks in the U.S. are all part of a continuous chain of transmission that began with the outbreak in Texas in January 2025. Gathering the necessary epidemiological data, genomic analyses and surveillance reports takes time.
But even if PAHO determines that the outbreaks are separate, the U.S. could still lose its elimination status if it fails to prove that it can interrupt the spread of measles quickly and consistently, says Dr. Demetre Daskalakis, an infectious disease specialist and former top official with the Centers for Disease Control and Prevention (CDC). And so far, he says, the U.S. is failing on this front.
"We do not have the capability to actually control measles, whether or not this is demonstrated through continuous measles transmission for 12 months," Daskalakis said in a press briefing this month. "So I'm going to say that elimination is already lost."
PAHO has said it plans to review the United States' measles elimination status this spring.
"Health freedom"
When asked whether the potential loss of measles elimination status was significant during a press call this month, Dr. Ralph Abraham, the principal deputy director of the CDC, said, "Not really."
Abraham said losing elimination status would not impact how the administration tackles measles. He said the administration supports the measles vaccine, but "You know, the president, Secretary [Kennedy], we talk all the time about religious freedom, health freedom, personal freedom. And I think we have to respect those communities that choose to go a somewhat of a different route."
But infectious disease experts and epidemiologists say the choice not to vaccinate is what's driving these outbreaks. Daskalakis says the resurgence of measles is being fueled by misinformation that undermines trust in vaccines.
And public health experts say losing elimination status is more than just symbolic. "I think it's really a comment on the state of the public health system," says Caitlin Rivers, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health. "We maintained elimination for 25 years. And so now, to be facing its loss, it really points to the cycle of panic and neglect, where I think that we have forgotten what it's like to face widespread measles."
And as measles cases rise, that will lead to more hospitalizations, more deaths and a greater toll on the public health system as a whole, says Dr. William Moss of the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health. He points to estimates suggesting that the average cost for a measles outbreak is $43,000 per case, with costs escalating to well over $1 million total for outbreaks of 50 cases or more. And fighting measles also takes resources away from other public health priorities.
Elimination vs. eradication
In 2000, PAHO declared measles eliminated from the U.S. because there had been no continuous domestic spread for more than 12 months. But the virus is still endemic in many parts of the world, and every year, there are U.S. cases brought in from abroad. So the virus has not been eradicated.
Compare that with the smallpox virus, which has not been reported anywhere in the world since the World Health Organization declared it eradicated in 1980.
Across state lines
Similar to Texas, the vast majority of cases in South Carolina have been in children and teens who are unvaccinated, leading to quarantines in about two dozen schools. Clemson University and Anderson University also have recently reported cases. And the virus has crossed state lines. North Carolina has confirmed several cases linked to the South Carolina outbreak. Across the country in Washington state, officials in Snohomish County told NPR they've linked six measles cases in unvaccinated children there to a family visiting from South Carolina.
Dr. Anna-Kathryn Burch, a pediatric infectious disease specialist with Prisma Health in Columbia, S.C., says it breaks her heart to see her state have such a large outbreak.
"I'm from here, born and raised — this is my state. And I think that we are going to see those numbers continue to grow over the next several months," she says.
Measles is dangerous. Here's how to protect yourself.
Measles is one of the most contagious diseases on Earth — more than Ebola, smallpox or just about any other infectious disease.
A person infected with measles can be contagious from four days before the telltale measles rash appears, until four days after. So the person could be spreading measles before they know they're infected. And when they cough, sneeze, talk or even just breathe, they emit infectious particles that can linger in the air for up to two hours, long after the infected person has left the room. On average, one infected person can go on to sicken up to 18 other unvaccinated people.
The best way to protect yourself is vaccination. The measles, mumps and rubella vaccine is very safe, and two doses is 97% effective — which means 97% of people will develop lifelong immunity against the disease. When vaccination rates are high in a community — 95% or more is considered ideal — that helps prevent measles outbreaks because there aren't enough vulnerable people for the virus to keep spreading. In Spartanburg County, S.C., the schoolwide vaccination rate for required immunizations is 90%.
Vaccination rates have been dropping in the United States. Nationwide, 92.5% of kindergartners had received the measles vaccine in the 2024-2025 school year, according to the CDC. In many communities across the country, those figures are much lower, creating the conditions needed for measles outbreaks to spread. Experts say all that's needed is one spark to ignite it.
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