Canadian health authorities have defended their immunisation schedule as the US considers altering its vaccine recommendations, amid escalating measles cases across North America.
Canadian health organisations are pushing back after Donald Trump ordered a rewrite of childhood vaccine guidance in the United States, saying the change is not backed by evidence and does not alter Canada’s own recommendations. The Canadian Paediatric Society said it continues to support the country’s routine immunisation schedule, which is set by health experts on the basis of scientific evidence, while the Canadian Public Health Association said parents should not delay or change their children’s vaccinations because of the U.S. move. The World Health Organization also warned that spacing out vaccines unnecessarily can leave children unprotected. Canada’s vaccine guidance remains unchanged, Health Canada said.
The dispute centres on measles, mumps and rubella vaccination, known as MMR. Under Canada’s immunisation guide, children aged 12 months to under 13 years should receive two doses of a measles-containing vaccine, either MMR or MMRV. The first dose is recommended at 12 to 15 months and the second at 18 months or later, but before school entry. The Public Health Agency of Canada says infants younger than 12 months are not routinely vaccinated against measles because the shot has not been established as safe and effective in that age group and maternal antibodies can interfere with the immune response.
Trump’s order would push U.S. agencies to recommend breaking the MMR vaccine into three separate shots and, more broadly, to space out some childhood vaccinations over more visits. That approach differs from current U.S. guidance, which recommends the first MMR dose at 12 to 15 months and the second at 4 to 6 years. The CDC says two doses of MMR or MMRV remain the best protection against measles, mumps and rubella.
The timing of the fight over vaccines is significant. Measles has surged across North America, with the Pan American Health Organization urging countries in the Americas to strengthen vaccination, surveillance and outbreak response. Canada reported 1,114 measles cases as of August 1 this year, while the PAHO said the region had recorded 47,459 confirmed cases by the end of the week ending July 18, making 2026 the worst year for measles in the Americas since 2004. Guatemala, Mexico, the United States and Peru have each reported far larger outbreaks than Canada.
Canada also lost its measles elimination status in November 2025 after more than a year of continued spread of the same strain, much of it in unvaccinated and under-vaccinated communities. Public health officials say the country can regain that status only after transmission is interrupted for at least 12 months. The broader lesson from both Canada and the United States, health agencies say, is that routine childhood vaccination remains one of the strongest defences against a disease that can spread quickly when coverage falls.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
