At a Glance
- Measles outbreak in South Carolina now 789 confirmed cases, surpassing the 762-case West Texas outbreak of 2025.
- 89 new cases added in the past week, and 557 people are in a 21-day quarantine.
- The virus has already crossed state lines, with confirmed cases in California, North Carolina, and Washington.
Why it matters: The rapid spread and low vaccination rates threaten the U.S. measles elimination status and risk outbreaks in schools with high numbers of unvaccinated children.
The latest measles outbreak in South Carolina has grown faster than any since 2025, now counting 789 confirmed cases. The surge has pushed the disease beyond state borders, prompting public health officials to warn of a looming threat to national elimination efforts.
Outbreak Overview
The South Carolina Department of Public Health reported that the majority of cases are concentrated in Spartanburg County, involving mostly unvaccinated individuals or those unaware of their vaccination status. Since Friday, 89 new cases have been confirmed, indicating the outbreak is still expanding.
- 557 people are currently in quarantine for 21 days.
- 170 people in Union County, North Carolina, are connected to a case at Shining Light Baptist Academy, a private Christian school with students as young as six weeks old.
Spread to Other States
By January, cases directly linked to South Carolina had been documented in California, North Carolina, and Washington. Probable cases were also reported in Ohio. Dr. Zack Moore, a state epidemiologist for North Carolina, highlighted the risk of cross-border transmission, especially in areas with low vaccination rates.
During a Jan. 21 media briefing, Moore said, “We know there’s a lot of back and forth travel, so that is certainly a concern.”
North Carolina health officials have reported 14 cases as of Tuesday, some with direct links to South Carolina. More than 170 people under quarantine in Union County are connected to a Shining Light Baptist Academy case.
Vaccination Rates and School Cases
Shining Light Baptist Academy has a vaccination rate of 60.1% among its students. Dr. Deborah Greenhouse, a pediatrician in Columbia, noted that low vaccination rates create a “tinder box” for measles. “If you have schools that have very low vaccination rates, you essentially create a tinder box for measles, because it is so incredibly contagious,” Greenhouse said.
The outbreak has forced 23 schools in South Carolina to quarantine students, with most sickened individuals being children and teenagers.
Public Health Response
Health officials have issued quarantine orders stemming from an unvaccinated child who attended school while contagious. The child contracted measles connected to the South Carolina outbreak. The response includes:
- 21-day quarantine for exposed individuals.
- Contact tracing to identify additional cases.
- Public education campaigns to increase vaccination rates.
Dr. Ralph Abraham, the new principal deputy director of the Centers for Disease Control and Prevention, appeared to downplay the issue during a Jan. 20 call with reporters. “It’s just the cost of doing business, with our borders being somewhat porous,” he said. “We have these communities that choose to be unvaccinated. That’s their personal freedom.” While he acknowledged the measles-mumps-rubella vaccine is “effective,” he did not explicitly encourage vaccination in outbreak areas.
Expert Commentary
Greenhouse emphasized the need to educate families: “I am very sad,” she said. “It emphasizes even more that we need to continue the work of trying to educate families in South Carolina and trying to get families to understand that the way we shut this down is by increasing our vaccination rates and by complying with isolation and quarantine.”
Dr. Diego Hijano, a pediatric infectious disease expert from St. Jude Children’s Research Hospital, explained how the MMR vaccine protects children from measles, but the article does not detail his statements.
Historical Context
The outbreak began in late September and picked up steam during the holidays. In 2025, the U.S. recorded 2,255 measles cases, the most in any year since 1991. So far in January, 416 cases have been confirmed nationwide, with the vast majority (93%) of patients being unvaccinated.
The outbreak’s rapid growth could threaten the U.S. measles elimination status, which could be lost as early as this fall if the virus is found to have circulated for a full year.
National Implications
The situation underscores the importance of maintaining high vaccination coverage and enforcing isolation measures during outbreaks. Public health officials continue to monitor the situation closely, urging residents to stay up to date with MMR vaccinations and to follow quarantine guidelines when exposed.
The outbreak also highlights the challenges of balancing individual choice with community health. As Dr. Abraham noted, “We have these communities that choose to be unvaccinated. That’s their personal freedom,” but experts warn that such choices can undermine collective immunity and lead to renewed outbreaks.
Key Takeaways
- 789 confirmed cases in South Carolina, the highest since 2025.
- 89 new cases in a single week, showing continued spread.
- Cross-border transmission has already occurred, with cases in three other states.
- Low vaccination rates in schools create high-risk environments.
- National elimination status could be jeopardized if the outbreak continues.
Public health agencies are urging increased vaccination and strict adherence to quarantine protocols to curb the spread.
