United States measles cases reach highest yearly total since 1991

The United States has reached 4,410 confirmed measles cases in 2026, the highest annual total since 1991. A recent weekly increase of 330 cases has contributed to this surge, with 451 hospitalizations reported so far this year.

Data from the Centers for Disease Control and Prevention (CDC) indicates that approximately 96% of cases involve individuals who are unvaccinated or have unknown vaccination status. Children and adolescents aged 5 to 19 represent 42% of the total cases, while adults aged 20 and older account for 41%.

A statistical discrepancy has emerged regarding mortality rates. While the CDC has officially recognized two measles-associated deaths nationally, Pennsylvania health officials reported six deaths between August and October 15, 2026. This divergence is attributed to a recent change in CDC policy, which now relies on final mortality data from the National Center for Health Statistics rather than preliminary reports from state health departments.