Canada is set to lose its international recognition as a country free of endemic measles, following a year-long outbreak that began in New Brunswick and spread across several provinces.

The nation first eliminated measles in 1998 and maintained that status for over two decades, meaning new infections were typically linked to international travel rather than local transmission. That changed last fall, when domestic spread continued beyond 12 months — a key threshold used by the World Health Organization to determine endemic status.

Since October 2024, more than 5,000 people across Canada have been infected, including two infants in Ontario and Alberta who contracted the virus before birth and later died. Public health officials say the resurgence underscores a dangerous decline in vaccination rates and growing distrust of science, fuelled by misinformation during and after the COVID-19 pandemic.

Experts warn that the loss of measles-free status could undermine public confidence in vaccination programs and lead to stricter monitoring from global health bodies. Several provinces, including British Columbia and Alberta, have urged families to ensure children’s immunizations are up to date.