Canada is likely to lose its measles elimination status. The U.S. could be next.

Canada is on track to lose its measles elimination status as an outbreak that began a year ago continues to spread.

The United States could follow in the coming months.

The Canadian outbreak began in October 2024 in New Brunswick, a province on the country’s eastern seaboard. As of Tuesday, more than 5,000 cases had been reported. Two babies have died.

Canada eliminated measles in 1998. The U.S. followed two years later, in 2000.

There are multiple criteria for losing an official measles elimination status , including the declines in vaccination rates observed in both countries.

But the most significant factor is having ongoing measles transmission for a full year.

“To really say that a country has lost the status, it takes 12 months of continuous transmission with the same genot