Canada is set to lose its official status as a country free of endemic measles, following a year-long outbreak that has infected more than 5,000 people across several provinces — a devastating setback after more than two decades without sustained transmission of the disease.
The outbreak, which began in New Brunswick in October 2024, has now reached every region of the country, with tragic cases including two infants in Ontario and Alberta who were infected in the womb and died shortly after birth.
Health experts say the resurgence of measles — a disease once thought to be eliminated in Canada since 1998 — is being driven by declining vaccination rates, fueled by misinformation, vaccine hesitancy, and pandemic-related disruptions in routine immunization.
The Pan-American Health Organization (PAHO), the regional arm of the World Health Organization, is expected to review Canada’s measles elimination status at a meeting in November. If revoked, it would mark the first time in 27 years that Canada has lost its measles-free designation.
“We haven’t managed to get ahead of the virus,” said Dr. Natasha Crowcroft, vice-president of infectious diseases and vaccination programs at the Public Health Agency of Canada. “This milestone highlights how important it is to rebuild our vaccination systems and regain elimination status.”
To reclaim its measles-free standing, Canada will need to demonstrate at least 12 consecutive months without community transmission, while also maintaining 95 per cent vaccination coverage — the level required to achieve herd immunity against one of the world’s most contagious viruses.
Countries like Venezuela and Brazil, which lost their measles-free status in 2018 and 2019, managed to regain it after five years of sustained immunization efforts, PAHO noted.
Experts warn that Canada’s experience should serve as a wake-up call. “Because we’ve lived without measles for so long, people have forgotten how serious it can be,” said Nicole Basta, an epidemiologist at McGill University and Canada Research Chair in infectious disease prevention. “This is a reminder of how quickly complacency can undo decades of progress.”
Dr. Cora Constantinescu, a pediatric infectious disease specialist in Calgary who leads a vaccine hesitancy clinic, said the outbreak has reignited awareness among health-care professionals. “We need to bring vaccination back to the forefront,” she said. “If you’d asked me ten years ago, I’d never have believed we’d see an outbreak of this size in Canada.”
The measles resurgence has also raised fears about potential declines in vaccinations for other diseases like polio and whooping cough. Public health officials are urging all Canadians — particularly parents — to check their immunization records and ensure that children are fully vaccinated.
“This is not just about measles,” Basta said. “It’s about protecting public trust in science and ensuring we don’t see the return of diseases we once defeated.”