This is a summary, written by members of the CITF Secretariat, of Canadian Blood Services’ Mid September 2022 report of data gathered from blood donations. The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

Consistent with the continued prevalence of Omicron variant its subvariant, infection-acquired seropositivity increased among blood donors to 62.4% by mid-September, up from 60% in the last week of August. These data come from Canadian Blood Services.

Key findings:

  • There was an increase over the 14-day reporting period from 61.2% in the first week of September to 63.62% by mid-September.
  • Vaccine-acquired (spike) antibodies were present in 100% of blood donors, consistent with the roll-out of third and fourth vaccine doses. Peaks occurred earlier in older age groups, likely due to policies to vaccinate older age groups earlier.
  • In the week of September 8-14, 2022, donors aged 17-24 had the highest seroprevalence rate (76.7%) of all age groups. Donors that were 60+ years old had the lowest seroprevalence rate 47%.
  • The seroprevalence rate increased in all provinces except New Brunswick and Newfoundland, possibly due to low numbers of samples tested.
  • Racialized groups continue to have higher seroprevalence compared with white donors (70.4% vs 62.3% in the week of September 8-14, 2022, 67.2% vs 60.1% from September 1-7).
  • Infection-induced seroprevalence was 64.5% among the most materially deprived in the week of September 8-14 and 62.3% among the least materially deprived in the same week.

The latest report builds on the August 2022 report and includes samples from 15,180 unique donors between the ages of 17 and about 60 who donated blood between September 1st and 14th, 2022, in all of Canada, excluding Quebec and the Territories.

It should be noted that individuals who choose to donate blood are generally in good health and are more likely to live in populous urban areas. Percentages were adjusted for test characteristics and population distribution.

Explore our interactive webpage updated every month, featuring the latest aggregated data gathered by the Canadian Blood Services and Héma-Québec on SARS-CoV-2 seroprevalence in Canada.