Canada has officially lost its measles elimination status after nearly three decades, following a year-long outbreak that the country failed to control, the Pan American Health Organisation (PAHO) announced on Monday. This development also means that the Americas region has lost its measles-free designation, though individual countries retain their status.
Over the past year, Canada has recorded more than 5,000 measles cases across nine of its ten provinces and one northern territory. Health experts had previously predicted that PAHO would revoke Canada’s status due to gaps in vaccination coverage.
“This represents a setback, but it is also reversible,” said Dr. Jarbas Barbosa, director of PAHO, part of the World Health Organisation.
Infectious disease specialists note that the outbreak is a warning sign. Isaac Bogoch of Toronto General Hospital highlighted lapses in public health outreach and the need to remove barriers to immunization. Measles is highly preventable, with 95% vaccination coverage required to achieve herd immunity. Two doses of the vaccine are 97% effective.
Health experts caution that falling vaccination rates exacerbated by pandemic-era skepticism may allow measles and other vaccine-preventable diseases to resurge, potentially leading to hospitalizations and deaths, especially among children, according to the research group KFF.
The Public Health Agency of Canada noted that although transmission has slowed, the outbreak has persisted for over 12 months, primarily affecting under-vaccinated communities. Authorities plan to boost vaccination coverage, improve data sharing, and strengthen virus surveillance systems.
Regional impact and recovery efforts
Alberta, one of the hardest-hit provinces, reported a 90% decline in cases from the peak, with only two active cases in recent weeks. Vaccinations since March have increased by 50% compared to last year.
For a country to retain measles-free status, it must halt the spread of the virus and report no locally transmitted cases of the same strain for at least 12 months, alongside maintaining high-quality surveillance systems.
The Americas had only regained measles-free status in 2024 after an outbreak in Brazil was contained. Other countries, including the U.S. and Mexico, have faced significant outbreaks this year, with declining vaccination rates noted in Europe and other wealthy nations.
The United States faces a January 20 deadline to prove it has stopped continuous transmission from a strain that emerged in Texas last year. Ongoing investigations aim to ensure new cases are not linked to that outbreak.
Experts warn that the loss of measles elimination status is a “step backwards”, highlighting the continued risk posed by vaccine hesitancy. Amesh Adalja of the Johns Hopkins Center for Health Security called it “a return to more primitive times” in terms of disease control.
The offices of Canada’s Health Minister Marjorie Michel, as well as Manitoba and Ontario two of the most affected provinces declined to comment.
