As the number of measles cases rises across the country, new projections suggest Canada could be on the brink of a significant outbreak if vaccination rates don’t improve. With measles already making appearances in various regions, experts warn of the potential for a “sizable outbreak,” ranging from dozens to thousands of infections, particularly in communities with low vaccination rates.
So far this year, at least 31 measles cases have been reported in Canada, marking the highest annual total since 2019 and more than double the number reported last year. Medical experts anticipate this number to climb further, especially with increased travel during March break.
According to modelling by a team at Simon Fraser University (SFU) in British Columbia, vaccine coverage below 85% could result in numerous cases within smaller communities and even hundreds if vaccination rates are lower. The SFU team shared their findings with federal public health officials, highlighting the potential severity of the situation.
One scenario outlined by the modelling indicates that in a 1,000-person community with a 75% vaccination rate, an outbreak could result in around 100 cases, leading to approximately 20 hospitalizations. Larger communities with vaccination rates as low as 60% could see up to 1,000 cases, escalating to nearly 3,000 cases with a vaccination rate of 55%.
Alarmingly, some Canadian communities have vaccination rates well below the national average, with data revealing rates below 50%, 40%, or even as low as 30% in certain areas.
Dr. Brian Ward from McGill University in Montreal predicts major outbreaks with “many hundreds of people” in the near future, likening the situation to a “forest fire” of infections. Quebec, particularly the Montreal area, has emerged as an early hotspot, with 21 reported cases prompting the province to launch vaccination clinics to curb local transmission.
Despite high overall vaccination rates in Quebec, certain areas, especially in Montreal, have alarmingly low uptake rates for the measles vaccine, increasing the risk of significant outbreaks. Dr. Luc Boileau, Quebec’s public health director, estimates that around 100,000 children in the province’s school system may not be fully vaccinated against measles.
Canada’s overall MMR vaccination rate has also declined, with only 79% of children receiving two doses by age seven in 2021, down from 87% four years earlier. Variability in vaccination coverage within different communities further complicates the situation, with some areas experiencing uptake rates well below 80%.
As Canada faces the prospect of imported measles cases from abroad, experts stress the importance of public health efforts to track and isolate cases, emphasizing that a community’s vaccination rate is the most significant factor in determining the size of an outbreak.
While the SFU modelling provides valuable insights, researchers acknowledge its limitations and emphasize the need for proactive measures to mitigate the risk of a measles outbreak in Canada. ( Source CBC)