admin So far this year, Canada has recorded 95 cases of measles (as of 21 February), with British Columbia, Manitoba, Ontario, and Quebec experiencing the worst of the outbreak, according to the latest data from the Public Health Agency of Canada (PHAC).
At this time last year, there were only four reported cases. By the end of 2024, Canada had logged a total of 146 cases.
“If you look at Ontario in the 2025 calendar year, it’s only February, and we already have roughly the same number of measles cases as in the whole of 2024. So no, we are not headed in the right direction,” said Dr Isaac Bogoch, an infectious diseases specialist at Toronto General Hospital.
Measles is one of the most contagious infectious diseases—more so than COVID-19, influenza, or chickenpox. This extreme transmissibility is why outbreaks spread quickly, particularly in areas with low vaccination rates.
“It’s so transmissible that if someone with measles was in a room and left, and an hour or two later another unvaccinated person entered, there’s a high probability they would be infected,” Bogoch explained. “It has a knack for finding unvaccinated or under-vaccinated people and communities.”
The virus spreads through the air when an infected person breathes, coughs, sneezes, or even talks. It can also be transmitted by touching contaminated surfaces or objects, according to PHAC.
Measles complications can be severe, including pneumonia, brain swelling, permanent hearing loss, and even death, particularly in young children or those with weakened immune systems.
Dr Theresa Tam, Canada’s chief public health officer, stressed the seriousness of measles, noting that around one in five infected children requires hospitalisation.
“Many parents haven’t seen measles firsthand,” she told Global News. “When children get measles, they’re miserable. They have a high fever, red eyes, feel very unwell, and develop the classic rash that starts on the face and moves down the body. It’s not a trivial illness.”
PHAC data shows that between 2 and 8 February, 34 new cases were reported in Manitoba, Ontario, and Quebec. Ontario also recorded three probable cases linked to an ongoing outbreak.
Two cases have been reported in British Columbia, both involving residents who recently travelled to Southeast Asia. Health authorities warn that passengers on an Air Canada flight on 11 February may have been exposed to the virus.
The data also reveals that 78 per cent of those infected were unvaccinated. The majority of cases occurred among individuals aged 5 to 17 (45 per cent), followed by those aged 18 to 54 (26 per cent) and children aged 1 to 4 (17 per cent).
What is driving the increase?
One key factor behind the spike in measles cases in Canada, Bogoch explained, is the significant global resurgence of the virus.
This global rise has led to measles being imported into Canada, triggering outbreaks, particularly in areas with unvaccinated populations.
“There’s a ton of measles circulating around the world. We’re also living in the most mobile era in human history, where people can travel anywhere, and we know that cases of measles will inevitably arrive in Canada,” Bogoch said.
Falling vaccination rates are also a major concern. Whether due to missed doses, lack of access, or misinformation, fewer people are getting vaccinated.
A study published in October 2024 in the Canadian Journal of Public Health found that coverage for the measles, mumps, and rubella (MMR) vaccine declined in 2023 compared to 2019, before the pandemic. Specifically, the rate for one MMR dose fell from 89.5 per cent to 82.5 per cent.
The most significant declines occurred in 2020 and 2021, and rates have continued to drop since the pandemic. This has left more people vulnerable to infection, weakening herd immunity. At least 95 per cent of the population must be vaccinated to prevent outbreaks effectively.
“Our results show a decline in routine vaccination coverage during the COVID-19 pandemic in Canada,” the study’s authors stated. “The pandemic and its associated vaccination campaign were accompanied by a widespread increase in misinformation—not just about COVID-19 vaccines, but vaccines in general.”
A highly effective vaccine
Measles was declared eradicated in Canada in 1998 after an extensive immunisation campaign.
However, in recent years, the disease has resurfaced due to falling vaccination rates, according to Health Canada. Most cases originate abroad, brought in by travellers who are either unvaccinated or under-immunised.
Since the virus spreads before symptoms appear and remains contagious for an extended period, outbreaks can be difficult to contain. This underscores the importance of vaccination, experts say.
“Cases should be preventable. We have a very effective vaccine—it’s extraordinarily safe, with decades of data proving its safety and efficacy. Nothing is 100 per cent perfect, but this is still an incredibly effective vaccine,” Bogoch emphasised.
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