In 2025, there were 2,255 documented cases of the measles in the United States, the most since 1991. More than 410 have been confirmed nationwide since the beginning of this year. Many of those cases — 789 — are due to an outbreak in South Carolina that began this past fall. Dr. Dana Hawkinson, medical director of infection prevention and control, explains how the virus is spread and how you get best protect yourself against the illness. | The University of Kansas Health System