Overview
- CDC data through Feb. 27 count 1,136 confirmed cases in 2026, with 1,130 reported across 28 jurisdictions and 6 among international visitors.
- About 92% of infections are in people who are unvaccinated or with unknown status, and 58 patients have been hospitalized.
- Cases span all ages but mostly affect youth: 278 under age 5, 653 ages 5–19, 198 adults, and 7 with unknown ages.
- South Carolina remains the epicenter with nearly 1,000 cases since October, largely concentrated in Spartanburg County with low vaccination coverage.
- Officials highlight that one MMR dose is about 93% effective and two doses about 97%, urging coverage near 95% to curb sustained transmission.