This is a summary written by members of the CITF Secretariat of Canadian Blood Services’ April 2023 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.

The latest CITF-funded seroprevalence report from Canadian Blood Services showed that approximately 80% of adult blood donors had infection-acquired seroprevalence in April, which is slightly higher than in March (78.8%). Younger donors (ages 17-24) continued to have the highest seroprevalence compared to other age groups.

Key findings:

  • Seroprevalence due to infection increased slightly in April to 79.4% from 78.7% in March, which is not statistically significant.
  • As in previous Canadian Blood Services surveys, significant gaps in infection-acquired seroprevalence rates between age groups continue to be seen. The youngest donors, aged 17-24, have the highest seroprevalence at 89.4%. Infection-acquired seroprevalence reached 81.2% in donors aged 40-59 and was 69% in donors aged 60 or above.
  • Self-declared Black, Indigenous, and racialized people continued to have higher seroprevalence (84.0%) than self-declared white donors (78.2%), though the gap narrowed slightly from March. Self-declared Asians had the highest infection-acquired seroprevalence at 84.8%.
  • The most materially deprived donors (based on postal code) continued to have higher infection-acquired seroprevalence, compared to the least materially deprived individuals (81.7% vs 79.0%), although the gap between them closed slightly.
  • All blood donors had anti-spike antibodies, which reflects Canada’s high vaccination coverage, combined with infection-acquired immunity.


The latest report builds on the March 2023 report and includes samples from 31,979 unique donors over the age of 17 who donated blood between April 1st and April 30th, 2023 across Canada, excluding Quebec and the Territories.

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.