When setting SARS-CoV-2 vaccine priorities, Canada should take a more nuanced approach that considers geographic and occupational risk exposures, as 75% of Canadian adults have at least 1 risk factor for severe COVID-19, argues an analysis in CMAJ (Canadian Medical Association Journal).
"Using risk factors for severe COVID-19 in a strategic vaccination strategy may not offer much refinement because of how widespread these conditions are. More detailed weighting of medical, geographic and occupational risks might be required if vaccination is constrained," writes Dr. Finlay McAlister, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, Alberta, with coauthors. "In particular, since the third wave of the COVID-19 pandemic appears to be disproportionately affecting essential workers in economically disadvantaged neighbourhoods, weighting of such risks may be necessary for equity goals to be met."
The authors looked at national data on more than 60 000 people to determine the presence of risk factors for severe COVID-19 in the Canadian population. While age is the most important risk factor for severe illness, three-quarters of adult Canadians have at least one other risk factor, and one-third have two or more. The most common risk factors were hypertension (23.1% of men and 21.1% of women) and obesity (21.7% of men and 20.2% of women). Although risk factors increased with age, the authors note that even in the 18-49 age group, 70.9% of men and 67.9% of women had at least one risk factor and 31% had at least 2 risk factors for severe COVID-19.
The authors acknowledge that vaccine prioritization decisions are as much an ethical question as a scientific one.
"We suggest that transparency in decision-making is important, especially where decisions vary across jurisdictions, to confirm that the rationale for decisions is driven by data and concordant with the shared values of local populations," the authors conclude.