A highly contagious disease once vanquished by vaccination is now on the brink of officially returning to North America. Canada is expected to lose its measles elimination status, and the U.S. might possibly soon follow.
This week, Canada reported new cases of measles tied to an ongoing outbreak—one that began 12 months ago. The year of continuous transmission means that Canada will almost certainly lose its measles-free designation, experts say. And though the largest outbreaks of measles in the U.S. this year have officially ended, the country could potentially still lose its status in 2026, too.
“As of today, it seems very, very likely that Canada will lose its measles elimination status, while the United States is also at substantial risk in the next 3 months,” Sten Vermund, chief medical officer at the Global Virus Network, a coalition of medical virologists focused on viral threats, told Gizmodo.
A resurgent enemy
Despite a highly effective vaccine for it, measles remains a serious public health threat across much of the globe. In 2023, it’s estimated to have sickened roughly 10 million people and killed over 100,000 worldwide, with most deaths occurring in unvaccinated children under five.
Some countries, through widespread vaccination programs, have kept measles largely at bay by stopping its local transmission. The U.S. officially eliminated endemic measles in 2000, while the Americas as a whole first achieved elimination in 2016. Canada earned its measles-free status in 1998. But so long as measles is endemic somewhere, the disease can hitch a ride on infected travelers and threaten to regain a foothold in locally eliminated countries, especially when vaccination rates start to decline. It’s a threat that’s now hitting close to home in the U.S.
Canada’s latest outbreak first began in October 2024 in the province of New Brunswick. Since then, the country has reported over 5,000 cases, nearly all of which are linked to the initial New Brunswick cluster. And though the flow of cases has significantly slowed down over time, it hasn’t stopped. On Monday, Canadian health officials reported 19 new cases during the week of October 18 (the most current data) and 136 recent cases across five jurisdictions.
The World Health Organization regularly evaluates whether countries can be deemed locally free of measles. Travel-related outbreaks can and do still occur in these countries, but it takes more than a year of ongoing transmission for the WHO to even consider revoking a country’s measles-free card. The Pan American Health Organization (PAHO), a subset of the WHO, will meet next month for its annual assessment of the region’s status. And given the current situation, Canada will probably lose its measles-free mantle.
What about the U.S.?
The immediate outlook is a bit less grim for the U.S., though still far from great.
Earlier this January, a large outbreak of measles began in Western Texas. More than 700 cases were ultimately documented before officials formally declared the outbreak over in mid-August. Another large outbreak occurred around the same time nearby in New Mexico, which saw roughly 100 cases before it appeared to die down in late September.
The trouble is, there have been many other measles clusters happening across the U.S. this year, and some are ongoing. All told, there have been roughly 1,650 cases reported—the largest tally seen since 1992—and dozens of outbreaks reported nationwide in 2025. At least three people died of measles in the U.S. this year as well, the first deaths recorded in a decade. There are current outbreaks in South Carolina, Illinois, Minnesota, Arizona, and Utah, with the latter two states sharing a cluster that’s now over 120 cases and counting.
Though the outbreak in Texas is over, it remains possible that health officials will link some of the current cases to it. This can occur if people in these states are found to be infected with the same or closely related strain of measles that sickened residents in Texas. If so, and if these cases last until January, the PAHO could very well decide to revoke the measles-free status of the U.S. early next year, too.
But even if this scenario doesn’t happen, experts are still worried about measles becoming endemic in America soon enough, given the sheer amount of transmission we’ve seen this year.
“I expect the US will lose its measles elimination status next year, as the U.S. in 2025 has already experienced almost 4 cases per 10 million, 87% of cases were related to an outbreak, i.e., not imported, and there have already been 43 outbreaks in less than one year,” Jessica Justman, an infectious disease specialist and epidemiologist at Columbia University’s Mailman School of Public Health, told Gizmodo.
The country’s federal public health system isn’t exactly in steady hands either. Earlier this year, President Donald Trump appointed Robert F. Kennedy Jr. to lead the U.S. Department of Health and Human Services, a man with a long history of misleading the public about the safety of vaccines, including the combined measles, mumps, and rubella (MMR) vaccine. And during the height of the Texas outbreak, both he and his allies downplayed its impact and touted unsupported treatments for the viral disease.
How to stop the return of measles
Formidable as measles is, we’ve long known how to best curtail its danger: vaccination.
It might be too late to stop the official return of measles in Canada or even the U.S. But that doesn’t mean that all hope is lost. Notably, Canada wouldn’t even be the first country in the Americas to have lost this status in the last few years, as both Brazil and Venezuela did recently. However, these countries have since regained their designation.
Though America certainly has a growing anti-vaccination problem, measles vaccination rates in the U.S. and Canada remain generally high (for now). The current outbreaks have occurred in regions where rates are much lower than average, such as Mennonite communities in Canada. In at least some of these communities, officials have said, residents aren’t necessarily opposed to vaccination but simply have less regular contact with doctors. And unlike the U.S., there are no major public health figureheads in Canada with a track record of anti-vaccination sentiment.
All of which is to say that a dedicated public health response can still convince people to get their measles shots. And Vermund expects that Canadian health officials will lay out a detailed plan to the PAHO to get things back on course.
According to Vermund, this plan should ideally include, among other things, stronger vaccination campaigns that target under-vaccinated regions like Alberta and Ontario, mobile clinics and school-based immunization drives, community engagement and public education to counter vaccine misinformation, and improved surveillance.
That same framework should also work to boost flagging vaccination rates in the U.S., too. But under the reign of RFK Jr., the Centers for Disease Control and Prevention has been turned into a shadow of its former self, and the ongoing shutdown of the federal government might further hamper any assistance that the CDC can provide to local and state agencies.
“A course correction for the U.S. will require an intensive vaccination campaign and funding to support the public health surveillance systems across all 50 states,” Justman said. “Neither of these seems likely in the current context.”
Though Canada will lose its status first, measles might have an easier time getting reestablished in its downstairs neighbor. If so, plenty more children and their families will suffer as a result.
English (US) ·