Measles is a highly contagious virus that can lead to serious health complications. Luckily, the virus can be kept in check with the use of vaccines, which are available to all Canadians and are a part of children's routine immunization schedules.
Dr. Meena Dewar, medical health officer at Vancouver Coastal Health (VCH), said that measles is important right now as they are seeing a worldwide resurgence in measles transmission and infection rates.
Dewar said this is mainly because of interruptions to the vaccine programs in many countries during the pandemic, particularly in the first few years of the pandemic.
Dewar reiterated that measles is a communicable disease that is highly infectious, causing serious respiratory infection that can lead to severe illness. Children are among the most vulnerable and can develop pneumonia and in some cases even encephalitis (brain inflammation).
The measles vaccine consists of two doses, Dewar explained. The first dose offers 90 per cent protection from the virus, and two doses amount to 95 per cent protection. Two doses are recommended for any individual born in 1970 or later.
Decline in vaccine rates
Dewar said that VCH’s two-dose vaccine rates have seen a stepwise decline, but clarified that it is not due to the pandemic.
In 2017, VCH began to see a decline in vaccination rates that remained consistent over the span of the pandemic.
Dewar said the reason for this was a change in children's immunization schedule.
Traditionally, children in Canada would receive their first measles mumps vaccines when they are 12 months old, then the second at 18 months. Then when the kids began Kindergarten, there was an opportunity to catch up any children who missed either their first or second dose – totalling in three chances to provide the vaccine.
In 2013, a decision was made to give the second vaccine dose at Kindergarten entry instead of 18 months old.
The change was because VCH started offering a combined vaccine offering protection from measles, mumps, rubella and varicella (MMRV).
Dewar said the primary reason for this is the response from the varicella portion of the vaccine is more effective when there is a longer period between doses.
While this vaccine offers greater protection, decreasing the number of opportunities for children to get vaccinated resulted in a coverage gap.
She said that according to VCH, the Coast Rural area (which includes the Sunshine Coast) has an 88 per cent one-dose coverage for measles and 77 per cent two-dose coverage.
Exposures in Canada
Dewar said there were approximately 10 recorded cases of measles in Canada in 2023, including one exposure at Vancouver International Airport.
She said that a number of these were importations, meaning the virus was brought into the country from a different place, adding that none of these resulted in widespread transmission.
She explained that importations are common in the present global scene.
“The virus is there worldwide, as people travel the virus will find its way to Canada as it does to other jurisdictions,” Dewar said.
While these importations are difficult to predict, Dewar said the important thing is that widespread transmission does not occur as a result of these exposures.
“And the reason we don't see widespread transmission is that in general, we have good population-level immunity,” she said.
Dewar highlighted that the provincial Health Gateway online tool can be used for researching immunization records for both adults and children.
Jordan Copp is the Coast Reporter’s civic and Indigenous affairs reporter. This reporting beat is made possible by the Local Journalism Initiative.
Correction: This story previously stated that the vaccine was reccomened to people born before 1970. We regret the error.
