Measles has continued its historic resurgence in the United States, with 2026 becoming the second consecutive year to shatter records for cases of the once-eliminated disease. Just over halfway through the year, the country has recorded at least 2,318 cases, surpassing last year’s total of nearly 2,300 and marking the highest count since 1991, according to data from the US Centers for Disease Control and Prevention. More cases have been documented in the past 18 months than in the previous 25 years combined, a staggering trajectory for a disease that was declared eliminated in the US in 2000.
Most of this year’s cases stem from outbreaks that began in 2025 and never fully subsided. South Carolina has reported more measles cases than any other state, driven largely by an outbreak that tore through Spartanburg County starting last October before finally winding down in April. That single outbreak sickened nearly 1,000 people, making it the largest the country has seen in decades. An outbreak along the Utah-Arizona border has also simmered for more than a year, and dozens of new outbreaks have erupted across nearly every state. The vast majority of infections — more than 90 percent — are among people who are unvaccinated or whose vaccination status is unknown.
For communities caught in the path of these outbreaks, the experience has been both frightening and eye-opening. The Reverend Scott Neely, whose Unitarian Universalist church sat at the center of the Spartanburg outbreak, learned on the day after New Year’s that someone with measles had attended the congregation’s annual Christmas brunch — an open potluck event with no guest list. Church members scrambled to identify attendees from a photograph and relay contact information to state health officials for contact tracing. Transmission appeared not to spread beyond that gathering, something Neely attributes to his congregation’s high vaccination rate. The episode underscored how intensive public health responses can be even when exposure is limited: In San Francisco, two cases in April required activation of nearly all case investigators, and one health official said her department could barely handle more than a single case without calling in additional staff.
Public health experts say the ongoing crisis reflects a broader failure to maintain vaccination rates sufficient to keep measles at bay. Dr. Andrew Racine, president of the American Academy of Pediatrics, called it an avoidable failure, noting that most cases are children who were never vaccinated. International health officials are expected to meet in November to assess whether the United States can still claim its longstanding status as having eliminated endemic transmission of the virus — a designation now hanging by a thread after years of declining immunization rates left pockets of vulnerability scattered across much of the nation.