In 2025, more than 5,400 Canadians contracted measles. Two infants died. On Nov. 10, the Pan American Health Organization confirmed what Canadian public health organizations had feared most: measles is once again endemic in Canada, and the elimination status we have held since 1998 is gone. Because Canada lost its status, the entire Region of the Americas lost its measles-free designation along with us.
Canada has long called itself a global public health leader. Last year, we recorded more than double the measles cases of the United States, despite having less than one-eighth of its population. That shouldn’t have been possible, and it didn’t have to be.
In my Master of Public Health coursework at the University of Chicago, I study how outbreaks of infectious diseases like measles unfold. Using mathematical models, we trace how a single case becomes 10, then 100, then thousands, when vaccination rates fall too low. The most effective way to stop an outbreak is also one of the simplest. Vaccines work because they prepare our immune systems to recognize a virus before it can make us sick.
Thanks to the measles, mumps and rubella (MMR) vaccine, most younger Canadians have never seen measles up close. Before the vaccine, almost every Canadian caught measles during childhood. It usually started with a high fever, a wet cough and red, watery eyes. A few days later, a rash would spread from the face down across the body. For most kids, it passed. But every year, children died and thousands were hospitalized. Measles can cause pneumonia, brain swelling that leaves lasting damage, and a weakened immune system that leaves the body vulnerable to other infections for years after recovery. Children under five are at the highest risk.
Vaccines are how we forgot all of this. When enough of us are vaccinated, we create what’s called herd immunity, the closest thing public health has to a force field. The virus turns up looking for someone to infect, knocks on a few doors, and finds them all locked. There are simply too few hosts for a disease to spread. In the case of measles, the threshold for herd immunity is 95 per cent. Surpassing it allows us to protect newborns too young for the vaccine, kids undergoing cancer treatment and people whose immune systems are compromised.
Canada has not been hitting that number for years. According to the Public Health Agency of Canada, MMR coverage among two-year-olds dropped from 89.5 per cent in 2019 to 80.4 per cent in 2024. Coverage of the second dose among seven-year-olds fell even further, from 86.3 per cent to 74.7 per cent over the same period. During the 2025 outbreak, almost all individuals who got sick were unvaccinated.
This is not a story about parents making bad decisions. The barriers are systemic.
This is not a story about parents making bad decisions. The barriers are systemic. Although routine childhood vaccinations in Canada are publicly funded, access is not equal. According to the most recent Childhood National Immunization Coverage Survey, two-year-olds in remote communities had significantly lower vaccine coverage than those in urban areas across all routine vaccines measured.
First Nations children living on reserves face additional structural barriers, including fragmented reporting systems and gaps in community health infrastructure. Beyond geographic challenges, Canada’s family physician shortage has made routine appointments difficult for millions. And while families struggle to access care, vaccine misinformation has a head start on every public health agency in the country. The result is what we are watching unfold right now. By the end of May, Canada had already reported more than 1,000 new measles cases, with Manitoba and Alberta bearing the worst of it.
The federal response has been to issue statements about coordinated efforts. That is not enough.
When I was about eight, my dad figured out the trick to getting me through vaccinations: ice cream. He’d promise me a scoop afterward, and it worked every time. By my second bite, the needle was a distant memory. Decades later, I’m still getting my vaccines. The bribe has been upgraded to a Tim Hortons run, but the deal is the same. If a double-double is what it takes to keep measles out of this country, the next round is on me.
If you are unsure whether you or your children are up to date on your vaccines, talk to your doctor. If you are an elected official, do more than “coordinate efforts.” Fund community health outreach in the communities where coverage is lowest. Invest in family medicine where measles is spreading. Treat measles like the public health emergency it is.
Canada can regain its measles elimination status, but only after we interrupt transmission for a full year. That requires hitting the 95 per cent herd immunity threshold. Every vaccine administered is a step toward rebuilding our force field. We have the science and public health infrastructure. We have decades of evidence that vaccines work. Canadian kids deserve a childhood like ours, free from a disease our grandparents had no choice but to endure. The path forward is one we can walk together.
