COVID-19 Antibody Results

Results from the CLSA COVID-19 Antibody Study are now being sent to participants by their preferred method of communication.

Participants who took part in the COVID-19 Antibody Study can expect to receive their results beginning in August 2021. Due to the large number of participants in the study, it is expected to take several months before all participants are notified.

The CLSA COVID-19 Antibody Study collected blood samples from more than 15,000 participants to determine the presence of antibodies that indicate immunity to COVID-19.

Antibodies are protective proteins produced by the immune system, the body’s defense mechanism, in response to a foreign substance. The presence of an antibody indicates an immune response. There are many types of antibodies made against the SARS-CoV-2 virus, which is the cause of COVID-19. The CLSA COVID-19 Antibody Study analyzed blood samples for two antibodies.

Participants will receive the results of their antibody tests along with an interpretation of test results. Additional information about SARS-CoV-2 antibody tests can be found here.

Antibody testing in the CLSA was done solely for research purposes (i.e., to determine how many people in the study have antibodies to this virus). Participants should continue to follow public health guidelines to prevent infection and the transmission of this virus.

If you have further questions about these tests, you can contact the CLSA by email at or by calling our toll-free line at 1-866-999-8303.

Thank you for your patience, ongoing participation and contributions to the study.