After an international health agency warned of the very high risk of measles spreading, Canadian experts say those who are not vaccinated are most vulnerable to catching the highly contagious disease.
The risk of measles spreading “remains very high” due to the expectation that more people will be travelling both domestically and internationally in coming months for religious events, according to the Pan American Health Organization (PAHO), a World Health Organization (WHO) body for the Americas, in a press release on Oct. 9.
“Measles cases have also risen globally in 2026, increasing the likelihood of imported cases through international travel and onward transmission in communities with low immunity,” according to the news release.
Dr. Isaac Bogoch, an infectious diseases specialist at Toronto General Hospital, called measles “a very transmissible infection.”
“It has a knack for finding non-immune individuals, and if people are travelling or potentially exposed to this infection and they’re not immune, there’s a high probability that that they’ll get infected,” Bogoch said in a video interview with CTVNews.ca on Wednesday.
The Public Health Agency of Canada recommends against giving measles-containing vaccines to infants under one year old, though children as young as six months old who are travelling to places with outbreaks may get them.
Dawn Bowdish, an immunologist at McMaster University in Hamilton, Ont., said it’s important for families to consider the serious risks for babies under one who may be too young to be vaccinated.
“Measles can have the most serious consequences in those that are too young to receive the vaccine,” Bowdish, who is the head of the Firestone Institute for Respiratory Health, she said in a video interview with CTVNews.ca on Wednesday.
Bowdish said measles is especially “dangerous” for those who are pregnant and unvaccinated.
“Anyone who’s pregnant and doesn’t know what their vaccination status is has to be really thoughtful before they travel to an area where there’s a high risk of contracting measles, because it can be deadly for the baby and really harmful for the mother,” she said.
The PAHO noted that there are “ongoing outbreaks, persistent gaps in vaccination coverage and the detection of measles cases in new geographic areas.”
‘Remarkably effective vaccine’
Most Canadians are immune to measles, Bogoch said, because most people born after 1970 received one or two doses of the vaccine.
“That provides robust and long-standing protection against measles,” Bogoch said. “Of course, it’s not 100 per cent perfect, 100 per cent of the time, but it’s a remarkably effective vaccine.”
Most people born before 1970 have recovered from a measles infection and therefore have immunity, Bogoch added.
“But those who remain unvaccinated, either by choice or because they’re too young to receive the first dose of a vaccine, those people are vulnerable,” he said. “Of course they can get the infection in Canada. It’s not a high risk, but it certainly is still there.”
After nearly three decades, Canada lost its measles elimination status in November 2025 because it failed to control a year-long outbreak. Countries need a 95 per cent vaccination coverage rate to achieve herd immunity.
Bowdish said she’s concerned that the measles vaccination percentage in Canada is “significantly lower than it needs to be,” adding that Canada needs more investment in public health and measures, such as mandating proof of vaccination for mass gatherings and school attendance.
“As we learned in the measles outbreaks in Canada, when there are pockets of people who have very, very high rates of not being vaccinated, you can have measles spreading very, very rapidly,” she said.
Where Canada ranks in Americas
The PAHO said between Jan. 4 and Oct. 3, 55,792 measles cases were confirmed, and 77 deaths were reported in 17 countries and territories within the Americas. The number of cases was 4.8-times higher compared to the same period in 2025.
Canada is fifth among the countries with the most reported cases, according to the PAHO.
The latest PAHO data showed five countries comprised 99.5 per cent of confirmed cases in the region. Guatemala topped the list, followed by Mexico, the United States, Peru and Canada.
In its news release, the PAHO urged countries to “strengthen vaccination, surveillance and rapid response measures as the risk of measles spread across the region remains very high.”
With files from Reuters
