The CLSA COVID-19 Antibody Study studies the impact of COVID-19 among older adults in Canada, a population that has been shown to be at greatest risk for severe outcomes from COVID-19 disease. The study collected blood samples from CLSA participants to estimate levels of immunity among older adults and provide a deeper understanding of some of the factors that affect their experience of the disease.
The CLSA COVID-19 Seroprevalence Study, also known as the COVID-19 Antibody Study, collected and analyzed blood samples from approximately 18,500 CLSA participants in 10 provinces. Study participants also completed a questionnaire, either by phone or online, that collected information about symptoms, risk factors, health-care use and the psychosocial and economic impacts of COVID-19.
CLSA participants were invited to take part in one of two ways:
- Providing a blood sample at a CLSA Data Collection Site
- Providing a blood sample from a finger at home, using a self-collection kit
Antibody testing involves analysing blood samples to determine if a person has been previously infected with the virus that causes COVID-19 or has been vaccinated. Participants provided a blood sample that was analyzed for the presence of COVID-19 antibodies.
Study Findings
COVID-19 SEROPREVALENCE STUDY
Between November 2020 and July 2021, the CLSA COVID-19 Seroprevalence Study (also known as the CLSA COVID-19 Antibody Study) collected and analyzed blood samples from CLSA participants in 10 provinces to test for the presence of antibodies that indicates infection due to the SARS-CoV-2 virus and/or vaccination.
Participant Resources
View information packages, consent forms and other documents relevant to your participation.
Frequently Asked Questions
Find answers to some of the most common queries about the CLSA.
This study was funded by the Government of Canada’s COVID-19 Immunity Task Force. The mandate of this task force is to describe how widespread the coronavirus infection is in Canada.
The COVID-19 Antibody Study recruited a random sample of participants already enrolled in the Canadian Longitudinal Study on Aging. The study is now complete.
Individual results from the CLSA COVID-19 Antibody Study have been sent to all participants. A summary of findings from the CLSA COVID-19 Antibody Study is available here.
The CLSA is designed to exist until 2059. All blood samples are labelled with a unique study number, not your name, at the time of collection. They will be stored long-term in freezers at McMaster University until relevant analyses are completed.
Research Team
Research Funding
The CLSA COVID-19 Seroprevalence study was conducted in partnership with the Government of Canada’s COVID-19 Immunity Task Force. The mandate of this task force is to describe how widespread the coronavirus infection is in Canada.
