Event Details

PHO Rounds: Blood Donor Surveillance: SARS-CoV-2 seroprevalence and beyond

Since the start of the pandemic, Canadian Blood Services has carried out a SARS-CoV-2 monthly seroprevalence study. It has collected over 800,000 samples from all provinces except Quebec (350,000 from Ontario) which were tested for antibodies to SARS-CoV-2 nucleocapsid (infection antibodies) and spike protein (vaccine or infection antibodies). It is the largest Canadian SARS-CoV-2 seroprevalence study. By May 2023, 79.2% (78.6, 79.9) of Ontario blood donors had infection antibodies. This was highest in 17-24 year olds (89.9% (88.6, 91.2)) and lowest in those 60+ (69.2 (67.8, 70.5)). In this Rounds presentation, the suitability of blood donors for public health surveillance will be described, Ontario SARS-CoV-2 sero-surveillance data will be presented, and the potential for blood donors to contribute to future public health research and surveillance will be discussed. The SARS-CoV-2 seroprevalence study was supported by funding from the Government of Canada through the COVID-19 Immunity Task Force.

Intended audience: Medical professionals involved in SARS-CoV-2 surveillance, planning and evaluating SARS-CoV-2 interventions including vaccination, public health physicians and nurses, epidemiologists, researchers.

By the end of this session, participants will be able to:

  • Explain the similarities and differences between blood donors and the general population in Canada
  • Describe key findings from the Canadian Blood Services SARS-CoV-2 seroprevalence study
  • Discuss the role that blood donors can play in public health surveillance post-pandemic


Presenter(s): Dr Sheila O’Brien

Dr. Sheila O’Brien is the Associate Director of Epidemiology and Surveillance at Canadian Blood Services. Her research includes epidemiology of blood transmissible infectious diseases and application to public health surveillance. She is the principal investigator of the Canadian Blood Services SARS-CoV-2 Seroprevalence Study. Dr. O’Brien is the vice-chair of the International Society of Blood Transfusion’s Transfusion Transmitted Infectious Diseases Working Party (ISBT TTID-WP). Dr O’Brien is an Adjunct Professor in the School of Epidemiology & Public Health, University of Ottawa, serves on the Transfusion Editorial Board, and is a Section Editor for Vox Sanguinis.


The opinions expressed by speakers and moderators do not necessarily reflect the official policies or views of Public Health Ontario, nor does the mention of trade names, commercial practices, or organizations imply endorsement by Public Health Ontario.


Public Health Ontario Rounds are a self-approved group learning activity (Section 1) as defined by the Maintenance of Certification Program of the Royal College of Physicians and Surgeons of Canada (RCPSC). In order to receive written documentation for Continuing Medical Education (CME) credits, please check “Yes” beside the question “Do you require CME credits?” on the registration form.

College of Family Physicians of Canada (CFPC) Affiliate Members may count RCPSC credits toward their Mainpro+ credit requirements. All other CFPC members may claim up to 50 Certified credits per cycle for participation in RCPSC MOC Section 1 accredited activities.

PHO Rounds are also approved by the Council of Professional Experience for professional development hours (PDHs) for members of the Canadian Institute of Public Health Inspectors (CIPHI).

For more information or for a record of registration for other Continuing Education purposes, please contact capacitybuilding@oahpp.ca.


Public Health Ontario is committed to complying with the Accessibility for Ontarians with Disabilities Act (AODA). If you require accommodations to participate in this event, please contact 647-260-7100 or capacitybuilding@oahpp.ca.

Chat icon


Capacity Building


Updated 11 Aug 2023