Results from the funded study: Best Practices for Mitigating the Impact of SARS-CoV-2 Variants of Concern

Pillar 8
Public Health, Health Systems and Social Policy Impacts

With variants of concern (VOCs) continuing to emerge and pose health challenges in Canada, scientists, including Dr. Nazeem Muhajarine from the University of Saskatchewan and CoVaRR-Net Pillar 8 Public Health, Health Systems and Social Policy Impacts Co-Lead, are strategizing on how to control their effects on the Canadian population.

Context and Relevance

Their recent manuscript, published in JMIR Public Health Surveillance, offers an “up to the point” analysis of variants of concern in Canada, conducted in June 2021. At that time, three forces were in tension: a push for greater vaccine uptake, newly emerging variants of SARS-CoV-2 virus and calls to “re-open the economy.” Now, 11 months later, the complexion of COVID-19 in Canada has changed yet again: 90% of eligible Canadians have at least one dose of vaccine, but only about 46% have had a booster dose; variants of concern, especially subvariants of Omicron, continue to emerge and pose a threat; and provinces and territories have dropped most, if not all, public health countermeasures.

In the present context, how relevant are these findings from June 2021? Most Canadians are vaccinated at this time with their primary doses; however, variants are continuing to emerge. The uptake of booster doses has stalled and most public health measures, such as mandatory masking indoors and proof of vaccine requirements, have been removed. In this context, the conclusions of this study are still relevant and informative.


The research team analyzed publicly available data to understand the geographical spread of the prevalence of VOCs in relation to vaccination uptake and indicators of public health measures. Specifically, they investigated the stringency of these measures and the mobility of populations in all provinces and territories. They identified three clusters of vaccine uptake and countermeasures:

  • Cluster 1 (consisted of the three Canadian territories) was characterized by moderate VOC prevalence, a higher degree of vaccine uptake and fewer countermeasures.
  • Cluster 2 (consisted of the Atlantic region and Quebec) was typified by low VOC prevalence, lower levels of vaccine uptake and moderate countermeasures.
  • Cluster 3 (Ontario, the Prairie provinces, and British Columbia) was characterized by the highest prevalence of VOCs (by a great margin compared to other clusters), moderate to low vaccine uptake, and moderate countermeasures.

The overall and variant-specific prevalence of COVID-19 was significantly different across the three clusters.


The researchers conclude that implementation of COVID-19 public health measures, including mass vaccination campaigns, is key to controlling VOC prevalence rates.

Further, surveillance of VOCs should continue across Canada, while accelerating the rollout and uptake of booster doses of vaccines. Achieving a balance in relation to the lifting and relaxation of public health countermeasures and up-to date vaccine coverage is prudent to preempt any future VOC-driven COVID-19 surges.

Governments and public health authorities need to continue to communicate the importance of socio-behavioural preventive measures such as masking when indoors and staying home when sick, and they need to have targeted and compelling messages to increase the uptake of booster doses of vaccines.

Adeyinka DA, Neudorf C, Camillo CA,Marks WN, Muhajarine N. COVID-19 Vaccination and Public Health Countermeasures on Variants of Concern in Canada: Evidence From a Spatial Hierarchical Cluster Analysis. JMIR Public Health Surveill 2022;8(5):e31968 doi: 10.2196/31968PMID: 35486447