Measles and Vaccination: What Happened in Spartanburg County

In late 2025 and early 2026, a major measles outbreak has been centered in Spartanburg County, South Carolina, and by early March the county-linked outbreak had grown to nearly one thousand confirmed cases. The surge followed months of rising exemption rates and low uptake in parts of the county, which left many school-age children vulnerable to infection.

Public health data show that the great majority of cases were recorded in people who had not received the measles vaccine; among outbreak-associated cases for whom vaccination status was known, about 95% were unvaccinated. One school involved in the outbreak had only 21 percent of students fully immunized, a level far below the 95 percent threshold that is generally needed to prevent sustained spread. Consequently, large numbers of students were quarantined when exposures were identified.

To slow transmission, health teams expanded vaccination clinics and recommended early MMR doses for infants aged 6–11 months in the affected area; post-exposure vaccination was used when appropriate. In January thousands more MMR doses were given across the state, and Spartanburg County saw a large increase in vaccinations. Hospitals have treated dozens of patients for measles complications, and public health officials have urged families to update records and accept offered vaccines so that communities can regain protection.

If vaccination coverage does not recover in low-uptake pockets, outbreaks will continue to arise where herd immunity is weak, and public health responses will be repeatedly required. Nevertheless, timely vaccination remains the most effective way to prevent severe illness and to protect those who cannot be vaccinated.