U.S. measles cases reach a 35-year high

U.S. CDC data show 5,182 confirmed measles cases in 2026 by November 5, the highest total since 1991 and more than twice the 2,289 cases recorded in all of 2025. Measles is extremely contagious but is effectively prevented by two MMR doses; national kindergarten coverage fell from 95.2% in 2019–2020 to 92.4% in 2025–2026, below the roughly 95% usually needed to interrupt spread. Cases are concentrated in under-immunized communities, and several states have reported deaths. The important signal is not only the national total but how local coverage gaps are rebuilding sustained transmission chains.