Amid a rise in measles cases in other countries and a handful of confirmed cases in Canada, the national public health agency "strongly advises" everyone check that they're fully immunized against measles, especially before travelling.

"As we head into the spring break travel season, the Public Health Agency of Canada is concerned that the global surge in measles activity, combined with the decline in measles vaccine coverage among school-aged children in Canada, could lead to more imported cases, potentially resulting in transmission of measles in communities in Canada," the agency said in an emailed statement Thursday.

Here's what to know about measles and how to make sure you and your children are protected.


Measles is one of the most contagious diseases in the world and is airborne. If someone with measles exits a room, others can be infected up to two hours after that person has left, said Shelly Bolotin, director of the Centre for Vaccine Preventable Diseases at the University of Toronto's Dalla Lana School of Public Health.

In 1998, measles was declared eliminated in Canada, meaning cases were no longer originating in this country. Infections occur here when someone contracts measles in another country and travels here.

Preventing spread of measles within a community requires 95 per cent of the population to be vaccinated.

"Because there's an increase in cases outside of Canada, then it's understandable that we're getting an increase in importations (of measles) as well," Bolotin said.

"What we need to make sure that we are doing is that our population is adequately protected so that when cases come in, they don't spread into large outbreaks (here)."

But measles vaccination coverage has dropped below 95 per cent in Canada, partly because of the disruption to routine childhood immunizations during the COVID-19 pandemic, the public health agency said.

The agency is aware of six cases of measles so far in Canada in 2024, it said.

"Measles can cause pneumonia as well as severe and permanent complications including deafness and brain damage resulting from inflammation of the brain (encephalitis)," the agency said.

"Measles can be a fatal infection. Children less than five years of age, adults older than 20 years of age, pregnant people and people who are immunocompromised are at higher risk for complications from measles."


Adults and children who have received two doses of measles vaccine, such as the measles-mumps-rubella (MMR) vaccine, are almost 100 per cent protected against getting the disease, the Public Health Agency of Canada said.

But the latest available data from 2021 shows that only 79.2 per cent of seven-year-olds have received two doses of vaccine.

"It is very important for parents to ensure their child(ren) receive a second dose of a measles-containing vaccine for full protection," the public health agency said.

The first dose of MMR vaccine is usually given to babies at 12 to 15 months and then again at 18 months or before the child starts school. The timing of the second dose depends on the province or territory.

But if a baby under one year of age will travel, they should get one dose of measles vaccine before leaving if they are at least six months old so they have some protection, said Bolotin.

That baby should still get the regular two-dose vaccination regimen after they turn one year old, she said.


People born before 1970 are generally assumed to have immunity to measles because they were likely infected while the disease was endemic in Canada.

But if they don't know if they've ever had measles and haven't had a blood test to confirm immunity, they should get a measles shot, especially if they are travelling outside of Canada, the public health agency said.

Adults born in or after 1970 likely received one dose of measles vaccine as a child.

But in 1996, two doses started to become standard. Many adults likely received that second dose if they were in school at the time.

The public health agency said that if you don't remember if you got a second dose, or if there's any doubt, talk to a health-care provider about getting a booster shot.

That's especially important if you will be travelling, the public health agency said.

People who don't know if they got a second dose of measles vaccine should also consider a booster if they are a health-care worker, in the military or attending college or university.

There is no harm in getting another dose of MMR vaccine, even if it turns out you did have two shots, said Bolotin.

"There's no relationship between adverse events and (the) more doses that you have. It's a very, very, very safe vaccine," she said.


A primary-care provider, such as a family doctor or nurse practitioner is the best person to ask about getting another measles shot as an adult, Bolotin said.

But if you don't have one, ask your local public health agency what you should do, she said.

In British Columbia, local public health units are providing measles vaccinations for both children and adults, Andy Watson, spokesperson for Dr. Bonnie Henry, the chief provincial health officer, said in an emailed statement.

Watson said people in British Columbia can also contact their local pharmacy.

Other public health agencies, including Toronto Public Health, are offering "catch-up" clinics for measles shots and other routine immunizations for children.

"For adults seeking measles vaccine who do not have a primary care provider, many walk-in clinics or travel medicine clinics also have the vaccine. Call ahead to a clinic to see if they have the vaccine," said Dr. Vinita Dubey, Toronto's associate medical officer of health, in an emailed statement.

This report by The Canadian Press was first published Feb. 23, 2024.

Canadian Press health coverage receives support through a partnership with the Canadian Medical Association. CP is solely responsible for this content.