Dr. Prabhat Jha holds a return envelope for the Ab-C study.
Dr. Prabhat Jha holds a return envelope for the Ab-C study.

A study led by Toronto researchers will be the first in Canada to use blood-based antibody testing on a large, random sample of Canadians to better understand a critical question for policy makers: how long does immunity to COVID-19 last?

The Action to Beat Coronavirus (Ab-C) study will track up to 10,000 Canadians over a six-month period in a collaboration between the Centre for Global Health Research at Unity Health Toronto, the University of Toronto and the Angus Reid Institute.

The study will examine COVID-19 immunity levels over time. There is still only preliminary data on the antibody response that occurs after exposure to the novel Coronavirus. The implications are enormous, particularly as countries lift physical distancing measures and vaccine development continues.

“This study will establish a national platform to assess interventions and progress, stand as a model for nationwide epidemiological studies, and inform public health decision-making and the general public,” said Dr. Prabhat Jha, director of the Centre for Global Health Research at St. Michael’s Hospital of Unity Health Toronto.

The first phase of the study is underway: an online questionnaire will be sent to over 10,000 Canadians drawn from the Angus Reid Forum, a nationally representative panel of Canadians, to gather information about their COVID-19 experience and request permission for mailing a blood spot collection kit.

Starting the first week in June, researchers will begin sending simple home kits to participants who agree to be tested. Participants are selected randomly, regardless if they have been exposed or not to COVID-19. They will self-administer a simple blood collection and return to the laboratory at St. Michael’s Hospital of Unity Health Toronto. The study will use at least two Health Canada-approved antibody tests to monitor levels of antibody titres. Participants will be able to see their results if they choose. Phase one will the study will collect a national estimate of people infected, and in turn will inform the infection fatality rate.

Four to six months later, a second round of questionnaires and antibody testing in the same individuals will provide information on ongoing transmission, changes in the immune status of the population and the durability of the immune response.

“Retesting four to six months later will document the short and medium-term immune profile of Canadian communities as well as ongoing transmission.” said Dr. Jha, who is also a professor of epidemiology at The Dalla Lana School of Public Health at the University of Toronto.

“This collaboration furthers research on Covid 19 symptoms in Canada originally conducted by our Institute in early April,” said Dr. Angus Reid, chairman of the Angus Reid Institute. “This very large sample study will answer critical questions about how many Canadians have been infected including those who have been asymptomatic.”

Canadians can find additional information on the study at AbCstudy.ca or by calling 1-833-TEST-ABC.

About St. Michael’s Hospital

St. Michael’s Hospital provides compassionate care to all who enter its doors. The hospital also provides outstanding medical education to future health care professionals in more than 27 academic disciplines. Critical care and trauma, heart disease, neurosurgery, diabetes, cancer care, care of the homeless and global health are among the Hospital’s recognized areas of expertise. Through the Keenan Research Centre and the Li Ka Shing International Healthcare Education Centre, which make up the Li Ka Shing Knowledge Institute, research and education at St. Michael’s Hospital are recognized and make an impact around the world. Founded in 1892, the hospital is fully affiliated with the University of Toronto.

About Unity Health Toronto

Unity Health Toronto, comprised of Providence Healthcare, St. Joseph’s Health Centre and St. Michael’s Hospital, works to advance the health of everyone in our urban communities and beyond. Our health network serves patients, residents and clients across the full spectrum of care, spanning primary care, secondary community care, tertiary and quaternary care services to post-acute through rehabilitation, palliative care and long-term care, while investing in world-class research and education. For more information, visit www.unityhealth.to.