US Officially Doubles Last Year’s Measles Numbers

The U.S. has confirmed 4,588 measles cases in 2026, more than double the 2,289 reported in all of 2025, according to an Oct. 23 update from the Centers for Disease Control and Prevention (CDC).

Cases span 47 jurisdictions and include 42 new outbreaks. Pennsylvania accounts for 1,338 cases, nearly 30% of the national total. Overall, 96% of cases occurred among people who were unvaccinated or had unknown vaccination status, while 59% involved people aged 19 or younger.

Infectious disease experts suspect substantial underreporting, highlighting the importance of measles vaccination and surveillance. Read more from The Hill here.