Measles cases in the United States reached their highest level in more than 30 years in 2025, with 2,242 confirmed infections. A particularly bad outbreak in West Texas that began in January of last year was a significant driver of those cases. Now, a surge of measles in South Carolina is on track to outpace the West Texas outbreak, which could mean another year of high measles cases.
“I’m concerned,” says Susan Kline, an infectious disease physician and professor of medicine at the University of Minnesota. “Based on the size of the current outbreak going on in South Carolina, I don’t think it bodes well for the current year.”
Around the country, states’ vaccination levels have been steadily declining in recent years. Coupled with the Trump administration’s hostility toward vaccines, the US is likely to see more measles outbreaks in the coming months and years.
The outbreak in South Carolina began last fall, when the state’s health department reported an initial eight measles cases on October 2. An outbreak is defined as three or more cases linked to a common exposure. That number climbed to 176 by the end of the year. As of January 20, the state has confirmed 646 cases—most of them in the “upstate” region, the northwestern corner of the state.
The West Texas measles outbreak resulted in 762 confirmed cases with 99 hospitalizations and two deaths among school-age children, both of whom were unvaccinated. The outbreak was officially declared over in August, seven months after it began.
“We feel like we’re really kind of staring over the edge, knowing that this is about to get a lot worse,” said Johnathon Elkes, an emergency medicine physician at Prisma Health in Greenville, South Carolina, in a January 16 call with reporters.
Measles is highly contagious, and the virus can linger in the air for hours after a person sneezes or coughs. Initial symptoms typically include a high fever, cough, and runny nose. The characteristic blotchy rash doesn’t appear until several days later. While most people recover from measles, the disease can be dangerous, especially for babies and young children. The virus can damage the lungs and severely weaken the immune system, leaving people vulnerable to pneumonia and other infections for several weeks to months. Pneumonia is the most common cause of death related to measles in children.
So far, 10 people in South Carolina have required hospitalization since the beginning of the outbreak there. That includes both adults and children. Cases have been identified on two college campuses, Clemson University and Anderson University, and the number of public exposure locations continues to grow by the week. In addition to the 646 confirmed cases, another 538 people in the state have potentially been exposed to measles and have been asked to quarantine at home while they wait to see if they develop symptoms.
Right now, the state is seeing new cases in the double digits identified every day, South Carolina’s state epidemiologist Linda Bell said during a January 21 briefing.
“We may be in this for certainly weeks more, and potentially months more, if we don’t see a change in protective behaviors,” she said.
There is no antiviral drug to treat measles. The best protection against the disease is vaccination with the measles, mumps, and rubella (MMR) vaccine. Among the 646 cases in South Carolina, 563 are unvaccinated, 12 have received one of two doses of the MMR vaccine, 13 are vaccinated, and 58 have an unknown vaccination status. The vaccine may not provide adequate protection for people with weakened immune systems.