South Carolina's measles outbreak nears 790 cases — making it the biggest in decades

The ongoing measles outbreak in South Carolina has reached a staggering 789 cases, making it the largest outbreak of the disease since the U.S. eliminated measles in 2000.

According to CNN, Texas previously held the record, with an outbreak that hit 762 cases between January and August 2025. That outbreak claimed the lives of two school-age children in the state. No deaths have been reported during the South Carolina outbreak yet.

The South Carolina Department of Public Health (DPH) announced the new case total on Jan. 27. The outbreak's epicenter is Spartanburg County, where over 750 cases have been reported and measles-vaccination rates among students are some of the lowest in the state.

"Complications are not reportable to DPH, but we have learned that 18 people, including both adults and children, have required hospitalization for complications of the disease since the beginning of the outbreak" in October 2025, the update says. "Additional cases required medical care for measles but were not hospitalized."

The statement adds that the vast majority of infections have occurred in unvaccinated individuals, although there are 60 individuals whose vaccination status is currently unknown. Of the remaining people infected, 695 are unvaccinated and 14 are partially vaccinated, having received only one of the two recommended doses of a measles vaccine. Twenty are fully vaccinated.

While the two-dose series is 97% effective at preventing measles, that leaves a slim chance of infection in fully vaccinated people who are exposed to the virus. That's why establishing herd immunity is important — it protects everyone in a community by curbing the virus's spread, thus lowering the chance of encountering the pathogen in the first place. A given community can reach herd immunity via both vaccination and prior infections, but only vaccination has the bonus of slashing the risk of death and long-term health problems from measles.

Given its recent and ongoing outbreaks, the U.S. may be on the cusp of losing its measles elimination status. That status is earned when a country reports no sustained, local transmission of the measles virus for at least a year.

U.S. officials are expected to meet with the Pan American Health Organization in April to determine if America has indeed lost its elimination status, the Center for Infectious Disease Research and Policy (CIDRAP) reported. If it does, the U.S. will join countries such as the U.K. and Canada, which have also recently lost their status due to low vaccination rates.

Dr. Ralph Abraham, the Centers for Disease Control and Prevention's (CDC) principal deputy director, expressed in mid-January that he was unconcerned about the U.S. potentially losing its elimination status, CIDRAP reported. He suggested that imported measles cases — from travelers to the U.S., for instance — were driving the rising measles rates.

Countries that have eliminated measles can still face sporadic, imported cases of the disease. But our elimination status hinges on whether the virus continues to spread consistently within the U.S. for at least 12 months. If an imported case lands in a community with adequate vaccination levels, the virus can't take hold.

For context, in 2000, the year measles was declared eliminated in the U.S., a total of 85 cases were reported nationwide, according to CDC data. In 2025, 2,255 cases were documented across the country. And given South Carolina alone has already reported hundreds of new cases in 2026, this year has already blown 2000's numbers out of the water.

"It breaks my heart to see that my state is the number one outbreak currently in the United States since the 1990s," Dr. Anna Kathryn Rye Burch, a pediatric infectious diseases physician with Prisma Health in South Carolina, told CNN.