Canada loses measles elimination status

Dr. Isaac Bogoch speaks on the ‘very disappointing outcome’ of Canada losing its measles elimination status and how it could be regained.

OTTAWA -- Canada has lost its measles elimination status after nearly three decades due to its failure to curb a year-long outbreak, the Pan American Health Organization said on Monday, a loss that also results in the Americas region losing the status.

Health experts last month predicted the Pan American Health Organization would strip Canada of the elimination status. The country has recorded more than 5,000 measles cases in nine of its 10 provinces and one northern territory. “This represents a setback, but it is also reversible,” said Dr. Jarbas Barbosa, director of the Pan American Health Organization, part of the World Health Organization.

Although the Americas region as a whole has also lost its elimination status, he said, individual countries keep their status. Belize, Bolivia, Brazil, Mexico, Paraguay and the United States are also facing active outbreaks.

“It’s a wake-up call for Canada,” said Isaac Bogoch, infectious diseases specialist at the Toronto General Hospital, that points to lapses in public health outreach and the need to lower barriers to immunizations.

Measles is a highly preventable disease when countries attain a 95% vaccination coverage rate. That is the level needed for a community to achieve herd immunity and protect those who are unable to receive the vaccine, which is 97% effective after two doses.

Health experts said spread of the virus, enabled by slipping vaccination rates in parts of Canada, is a harbinger of a resurgence of more vaccine-preventable illnesses in a population increasingly skeptical and mistrustful of vaccines since the COVID-19 pandemic.

Losing the status serves as a warning that measles could become endemic, continuously circulating and leading to hospitalizations and deaths, particularly among the most vulnerable children, according to health policy research group KFF.

The Public Health Agency of Canada in a statement said, “while transmission has slowed recently, the outbreak has persisted for over 12 months, primarily within under-vaccinated communities.”

It said it would focus on improving vaccination coverage, strengthening data sharing, and enabling better overall virus surveillance efforts.

STEP BACKWARD IN TIME

“Loss of elimination status is a step backward and a return to more primitive times, where voices from the Dark Ages continue to attempt pull us,” said Amesh Adalja, senior scholar at the Johns Hopkins Center for Health Security.

A spokesperson for the province of Alberta, one of the worst-affected Canadian provinces, said cases are down more than 90% from the peak with only two active cases in Alberta for the past several weeks. It said vaccinations since March are 50% higher than a year earlier.

To be considered measles-free, a country must stop the spread of the virus and be free of locally transmitted cases of the same strain for 12 months or greater, in addition to having high-quality surveillance systems.

The United States and Mexico have had significant measles outbreaks this year, with thousands of cases and a handful of deaths. Other wealthy countries including those in Europe have also been facing declining measles vaccination rates.

The Americas region only regained its measles-free status in 2024, after an outbreak in Brazil was stopped.

To retain its elimination status, the United States has a deadline of January 20 to prove it has halted continuous transmission of the strain that started in Texas last January 20 that kicked off a large outbreak, according to Dr. Demetre Daskalakis, a former U.S. Centers for Disease Control and Prevention immunization official.

The U.S. will also need to prove that ongoing cases are not related to the Texas outbreak. Investigations are underway to determine that, he said.

Measles vaccination rates in the U.S. among kindergartners have been on the decline, government data shows.

The office of Canada’s Health Minister Marjorie Michel declined to comment.

Manitoba and Ontario, two of the hardest-hit Canadian provinces, did not immediately respond to requests for comment.

(Reporting by David Ljunggren in Ottawa, Julie Steenhuysen in Chicago, Jennifer Rigby in London and Sriparna Roy in Bengaluru; Editing by Paul Simao, Caroline Humer and Bill Berkrot)