Here’s how measles cases are spreading across Canada

A dose of the measles, mumps, and rubella (MMR) vaccination awaits the next patient during a vaccine clinic at Southwestern Public Health in St. Thomas, Ontario, Canada, on Tuesday, March 4, 2025. (Geoff Robins/The Canadian Press via AP)

Measles cases appear to be unrelenting in certain parts of the country as infections continue to climb, according to government health officials.

Saskatchewan recorded 15 new cases this week, more than doubling its total to 27 infections this year. Three quarters of the infections are in children, according to Saskatchewan’s top doctor. The youngest to contract the disease was just five months old.

“Children under six months cannot get the vaccine. So, we’ve had exposure to infants who are at higher risk and cannot be vaccinated because families and communities around them are unvaccinated,” said Saskatchewan chief medical health officer Dr. Saqib Shahab.

All but one case have been reported in unvaccinated patients.

Initial transmission began in rural areas of southern Saskatchewan, but the disease is now spreading across the province, according to medical health officer Dr. Simon Kapaj.

“The risk is not just rural, but it’s across the province,” Dr. Kapaj said.

The Saskatchewan Health Authority has been working with communities to increase vaccine uptake where measles cases have been identified. Kapaj said the campaign appears to be working.

“More people are getting immunized, and more people are reviewing their immunization records,” he said.

In Ontario, transmission continues to balloon. This week the province recorded nearly 200 new cases to reach a total of 1,440 infections since the outbreak began in October.

“In the particular communities affected, they have historically not vaccinated themselves or their children,” said Ontario Chief Medical Health Officer Dr. Kieran Moore.

A large portion of transmission is taking place in rural communities in southwestern Ontario, mostly infected unvaccinated infants, children and teenagers.

“Prevention is the best medicine, and we have very effective and safe vaccine against measles,” Dr. Moore said.

Vaccines are not mandatory in Canada. However, Ontario and New Brunswick require proof of immunization for kids to attend daycare and school.

This week, 920 secondary school students in the Waterloo region were suspended due to outdated vaccination records.

Alberta Medical Association hosted a panel discussion this week to raise awareness around measles vaccines after the province surpassed 300 total infections.

Routine measles vaccines are administered in two doses, one at 12 months old and another at 18 months old. MMR vaccines protect against measles, mumps and rubella.

If children missed their routine vaccinations, doctors recommend they still get their two doses.

“Children can get brain inflammation or encephalitis from measles,” said Edmonton pediatrician Dr. Tehseen Ladha.

“This can cause long term disability in those children. So we’re looking at children having blindness, seizures, brain damage, lasting effects from contracting the measles virus.”

Health officials traced the outbreak back to a gathering in New Brunswick last fall. The province has yet to record a new measles case this year.

In Quebec, the government declared the measles outbreak over after going more than 32 days without a new case.

This week, Nova Scotia and the Northwest Territories recorded their first case of measles since the outbreak began.

Those born before 1970 are considered to have natural immunity due to widespread measles outbreaks at that time.

According to Canada’s immunization guide, susceptible adults born in or after 1970 should receive one dose of vaccine if they are unvaccinated. Adults with a greater risk of measles exposure due to travel or their workplace should receive two doses.