In the wake of a measles outbreak in Canada that has infected thousands of people over the past year, an international health agency revoked the country’s measles-free status on Nov. 10, 2025.

The Pan American Health Organization, which serves as the World Health Organization’s regional office for the Americas, made this announcement after the agency’s measles elimination commission met in Mexico City to review the latest public health data.

As a global health epidemiologist who…

Kathryn H. Jacobsen, MPH, PhD (Epidemiology, University of Michigan), is Professor of Health Studies and holds the William E. Cooper Distinguished University Chair at the University of Richmond. Her research...