Pan American Health Organization

Rule Changes

Issued Feb epidemiological alert on regional surge

The United States declared measles eliminated in 2000—the culmination of decades of vaccination campaigns against the most contagious virus known to infect humans. On January 22, 2026, that achievement formally entered jeopardy when the country passed one year and two days of continuous transmission starting in West Texas. As of mid-February 2026, the crisis has accelerated with CDC confirming 910 cases across 24 states so far this year—90% outbreak-associated—while South Carolina's outbreak exploded to 950 cases by February 13, prompting a looming April PAHO review likely to revoke elimination status.

Updated Feb 15