Get your two doses of measles vaccination: health chief

Canada's chief medical officer of health is warning people to make sure they have had two doses of measles vaccine, especially if they are travelling. That message, coming just before the heavy travel period of March break, is urgent this year with cases of measles spiking around the world and vaccination rates lagging, including across Canada.

It is also potentially complicated. Many adults are not aware of their vaccination status, and particularly whether they have had one or two measles vaccines. As well, a growing percentage of the population is without family doctors, making it more difficult to access care.

Measles can cause serious illness and even be deadly. Among potential severe complications are pneumonia, deafness and brain damage caused by inflammation of the brain.

It is also one of the most contagious of all known infections. People can become infected hours after entering a room where another person with measles has been. Because of that, travel makes people particularly susceptible.

In a statement, chief public health officer Dr. Theresa Tam noted a 79 per cent increase in the number of global measles cases in 2023 compared with 2022, notably across Europe.

“As we head into the spring break travel season, I am concerned that the global surge in measles activity, combined with the decline in vaccine coverage among school-aged children in Canada, could lead to an increase in imported measles cases, potentially resulting in transmission in communities in Canada,” Tam's statement said. “I strongly advise everyone in Canada to be vaccinated with two doses of a measles vaccine, especially before travelling.”

Canada eliminated measles through high vaccination rates, but it can easily arrive in this country after an unvaccinated person travels to a country where it is circulating and brings it back.

With vaccination rates dropping, one case can turn into many. Vaccination coverage has dropped in Canada below the 95 per cent mark considered necessary to prevent it from spreading. Only 79.2 per cent of seven-year-olds in Canada have received two doses.

As of Feb. 23, Tam said, there had been six measles cases in Canada, some of them leading to hospitalization. Most of those cases involved unvaccinated or under-vaccinated children who travelled internationally.

Ottawa Public Health said “compliance” for measles — individuals have both received and reported required immunizations for their age — is 62 per cent among Ottawa students born in 2016 and 92 per cent for those born in 2006. Those are the two cohorts currently under surveillance by public health officials.

That means about 5,200 students in those two age groups are not yet fully vaccinated or have been vaccinated and haven't reported it.

Public health sent more than 16,000 letters to students in those two age groups last fall and is sending more than 11,000 second notices to those who didn't respond the first time.

The most recent case of measles in Ottawa was reported in 2019.