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Canada has lost its measles-free status following a year of ongoing measles transmission, the Pan American Health Organization (PAHO) announced today. As a result, the entire region of the Americas is no longer measles-free. The Americas became the first region in the world to be declared free of the disease in 2016, following a 22-year regional campaign that relied on mass vaccination against measles, mumps and rubella. “This loss represents a setback—but it is also reversible,” PAHO director Jarbas Barbosa said today at a press briefing. On supporting science journalism If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today. So far this year, Canada has confirmed 5,162 measles cases. In response to PAHO’s declaration, the Public Health Agency of Canada said in a statement that it was working with PAHO and federal and local authorities to improve vaccination coverage, strengthen data sharing, enhance surveillance and provide evidence-based guidance. “Canada can re-establish its measles elimination status once transmission of the strain linked to the current outbreak is interrupted for at least 12 months,” the agency’s statement said. In addition to Canada, active measles outbreaks are currently underway in Belize, Bolivia, Brazil, Mexico, Paraguay and the U.S. Health experts have warned that the U.S. has been on shaky ground since a 762-case outbreak that began in West Texas in late January 2025; that outbreak was declared over on August 18. In 2025 the U.S. has had 1,681 measles cases, the majority of which were detected in Texas, Arizona and New Mexico. Health officials are currently investigating other ongoing outbreaks in South Carolina and Utah. If those are found to be linked to the outbreak that began in late January, the U.S. could lose its measles-free status for the first time in 25 years. This is not the first time the Americas has lost its measles elimination status. In 2018 and 2019 Venezuela and Brazil, respectively, temporarily lost their elimination status after major outbreaks. The region regained its measles-free designation in 2024—until now.
