On Nov. 10, 2025, the Pan American Health Organization (PAHO) revoked Canada’s measles elimination status. More than 5,000 cases have been reported since the outbreak began in October 2024. After a quarter century of controlling measles spread, Canada failed. The U.S. will likely soon join its northern neighbor in this ignominious designation, thanks to the resurgence of the anti-vaccination movement, which has been given new clout with Robert F. Kennedy Jr. at the helm of the Department of Health and Human Services (HHS).

Measles is the most highly-contagious disease known to science. If 10 unvaccinated people are in a room with an active case, nine will go on to become infected. In 2025, 12% of the 1,700 plus U.S. measles cases were hospitalized, with the highest rate, 22%, among children younger than 5 years old. Three people have in the U.S. and in Canada. include pneumonia, encephalitis, , and rarely, a fatal neurological disorder, subacute sclerosing panencephalitis (). Measles also has an insidious capability to cause “”, whereby immune responses to other pathogens are erased by the virus, leaving an individual susceptible to conditions they once had immunity to.