South Carolina health officials on Monday declared the end of a monthslong measles outbreak during which 997 cases were recorded.
The outbreak began in October, with the last case reported on March 15. Officials are required to wait to see if 42 days pass without a new case before declaring the end of an outbreak. The 42-day mark came at the start of this week, the South Carolina Department of Public Health said.
The vast majority of the patients in the outbreak, at 932 people, were unvaccinated. Nineteen had an unknown vaccination status. The remainder were vaccinated, with 20 patients having received one dose of the measles, mumps and rubella (MMR) vaccine, 25 with two, and one person with three, state officials said.
Officials recommend that people get two doses of the MMR vaccine. One dose is considered 93% effective against measles, while two doses are considered 97% effective, according to the Centers for Disease Control and Prevention.
The outbreak spurred a jump in vaccination rates in South Carolina. In Spartanburg County, which accounted for 940 of the cases in the outbreak, healthcare personnel gave out 3,788 more doses of the MMR vaccine than the year prior, a 93.6% year-over-year increase, state health officials said.
In the upstate region where Spartanburg County is located, 14,745 more doses of the vaccine were given out than the year prior. Statewide, 81,096 vaccinations were administered, a 31.3% year-over-year increase.
South Carolina health officials said the outbreak affected seven counties and seven school districts, with 33 schools having measles exposures and 874 students asked to quarantine at some point during the outbreak.
The outbreak began picking up steam in mid-November, when South Carolina began recording double-digit numbers of new cases each week, before peaking in January. In the first four weeks of 2026, health officials recorded 186, 203, 175 and 92 new measles cases.
The only other states with cases in the triple digits are Utah at 425, Texas at 180 and Florida at 134.
