The U.S. has recorded 2,318 measles cases in 2026, the highest number since 1991, according to the Centers for Disease Control and Prevention (CDC). The surge marks a significant rise from the 2,289 cases reported in 2025, with outbreaks ongoing in 45 states, including central Virginia and Lancaster, Pennsylvania. Three deaths were reported in 2025, the first since 2015, involving two unvaccinated children in Texas and an unvaccinated adult in New Mexico.
Part 1: Immediate Action & Core Facts
The CDC confirmed that 93% of cases this year involved unvaccinated individuals or those with unknown vaccination status, while 3% had received one dose and 4% had received two doses. The majority of cases (50%) occurred among people aged 5 to 19, with 31% in adults 20 and older. The top five states for measles cases are South Carolina (670), Utah (518), Texas (182), Virginia (176), and Florida (141). Idaho has the lowest vaccination rate at 78.5% and reported three cases this year.
Part 2: Deeper Dive & Context
Vaccination Rates and Herd Immunity
Health experts attribute the rise in cases to declining vaccination rates, which weaken herd immunity. Dr. William Moss of Johns Hopkins Bloomberg School of Public Health stated that high vaccination coverage had previously protected unvaccinated individuals, but pockets of susceptible people now allow measles to spread rapidly. The CDC defines an outbreak as three or more linked cases, with Pennsylvania reporting 132 cases, including 27 in the past week.
Policy and Public Health Response
The Trump administration has requested the Pan American Health Organization to delay its review of the U.S.'s measles elimination status from April to November 2026. The U.S. achieved measles elimination in 2000, but recent outbreaks risk losing this designation. The Department of Health and Human Services (HHS) has pledged support for outbreak responses, including laboratory testing and coordination with state and local partners.
Political and Social Perspectives
Sen. Bill Cassidy (R-La.) blamed the rise in cases on deliberate efforts to undermine public health measures, while health officials emphasize the safety and effectiveness of measles vaccines. The American Academy of Pediatrics warned that the crisis disproportionately affects children, with babies hospitalized due to pneumonia. The CDC has not provided separate percentages for unvaccinated versus undervaccinated individuals.
Geographical Shifts and Ongoing Outbreaks
The 2026 outbreaks show a geographical shift from 2025, when Texas was the epicenter. South Carolina now leads with the most cases, primarily in Spartanburg County. Virginia’s outbreak appears to be slowing, with no new cases since July 4.