COVID-19 Antibody Study FAQ

CanPath and its regional cohorts are conducting a COVID-19 antibody study of 20,000 participants across Canada.

COVID-19 Antibody Study Overview

What is the CanPath COVID-19 Antibody Study?

COVID-19 is an unprecedented public health challenge, and it is important that scientists and policymakers understand how prevalent this disease is among the general public. This study aims to find out how many Canadians have developed antibodies to the SARS-CoV-2 virus, the virus that causes COVID-19, by measuring antibodies from a donated blood spot sample. The study also includes a questionnaire that has questions about symptoms you may have experienced, testing, treatment, and also how the pandemic and physical distancing requirements have affected your daily life and well-being. We will also be asking questions about access to vaccines, and whether you have received a COVID-19 vaccine. This study will capture important data that will support researchers who are working on projects related to the COVID-19 pandemic. This data may also be used in conjunction with the questionnaire data and biological samples you have provided to us in the past.  

All of the regional cohorts of the Canadian Partnership for Tomorrow’s Health (CanPath, formerly called the Canadian Partnership for Tomorrow Project) are participating in this study. This includes Atlantic PATH, CARTaGENE (Quebec), the Ontario Health Study, Alberta’s Tomorrow Project, the Manitoba Tomorrow Project, and the BC Generations Project.  

Who is funding the CanPath COVID-19 Antibody Study?

CanPath’s COVID-19 Antibody Study is funded by the Government of Canada, through Canada’s COVID-19 Immunity Task Force, and by the Canadian Institutes of Health Research. CanPath also receives national funding from the Canadian Partnership Against Cancer.

When will this study be conducted? 

The blood spot samples will be collected from participants between December 2020 and June 2021. For those selected to partake in the CIHR-funded seroprevalence study, a second and third blood spot sample will be collected 6 and 12 months after the first sample is collected. 

Why is CanPath, a cancer and chronic disease study, participating in COVID-19 research?

This serology study aims to find out how many Canadians have developed antibodies to the SARS-CoV-2 virus, the virus that causes COVID-19. The results of this study will show who has been exposed to the virus, which risk factors affect exposure and why immune systems respond differently to the virus.   

In addition to understanding the direct health impacts of COVID-19 infection, we see growing evidence that there may be links between infectious diseases (like viruses and bacteria) and non-infectious chronic diseases (like diabetes, cardiovascular disease and cancers). We hope that comparing the findings of our study with data on health and lifestyle factors will help determine whether a coronavirus infection may have long-term effects on chronic disease.  

As a longitudinal study following participants for up to 50 years, CanPath and its regional cohorts are uniquely positioned to investigate the long-term effects of COVID-19 on Canadians. 

Didn’t I just complete a CanPath COVID-19 study? 

Yes. Over 100,000 CanPath and regional cohort participants completed the CanPath COVID-19 Questionnaire. Thank you! The information collected by this questionnaire is providing researchers and public health professionals with great insights into how the pandemic has affected the health and well-being of Canadians. This will help them understand how best to respond to the current COVID-19 pandemic as it evolves, and will also inform future pandemic responses. 

Now, CanPath and its regional cohorts are conducting a new COVID-19 serology study to see which Canadians have developed antibodies to the SARS-CoV-2 virus, the virus that causes COVID-19. This study aims to find out who has been exposed to the virus, which risk factors affect exposure and why immune systems respond differently to the virus.  

This new study builds on the information already captured by the previous COVID-19 questionnaire, including potential sources of exposure to the virus, such as those experienced by healthcare workers.  

Has the COVID-19 pandemic adversely affected your initial objectives and how have you adjusted your objectives and work plans? 

At CanPath, we are fortunate to have an existing and engaged cohort. We did not anticipate doing this kind of work, but we were able to pivot right away. Our data is being used to inform policies and practices with various organizations, such as the Public Health Agency of Canada (PHAC).

Study Participation

Who can participate in the COVID-19 Antibody Study? 

Only current participants of CanPath and its regional cohorts are invited to contribute to this study. Participants will receive communications directly from their regional cohort if they are selected to participate in the COVID-19 Antibody Study.  

Can I participate in the COVID-19 Antibody Study if I have received a COVID-19 vaccine? 

Yes. If you have received an invitation to participate in the COVID-19 Antibody Study from your regional cohort, you can participate whether you have or have not received a COVID-19 vaccine. The questionnaire will ask if you have received a COVID-19 vaccine and this information will be linked to your blood spot sample.  

Can I participate in the COVID-19 Antibody Study if I have not had COVID-19? 

Yes. If you have received an invitation to participate in the COVID-19 Antibody Study from your regional cohort, you can participate whether you have or have not received a positive COVID-19 test result. The questionnaire will ask if you have been tested for COVID-19 and what the results were, and this information will be linked to your blood spot sample. 

Can I participate in more than one COVID-19 research study? 

Yes. You can participate in the CanPath COVID-19 Antibody Study even if you are participating in other COVID-19 research studies.  

Blood Spot Samples & Antibodies

What is a blood spot sample? 

A blood spot sample is a process where a few drops of blood are collected on a piece of filter paper and dried. In this study, blood will be collected through a finger prick. 

Why am I being asked to give a blood spot sample? 

Your blood spot sample will be used to conduct a serology test, also known as an antibody test. 

What is serology or antibody testing? 

Serological tests do not detect the SARS-CoV-2 virus (the virus that causes COVID-19) itself. Instead, they detect the antibodies your immune system produces in response to an infection or after receiving a vaccine. Serology tests are also known as antibody tests. 

The immune response to a virus involves the creation of different types of antibodies produced at different stages of an infection:  

  1. Early antibodies, called IgM antibodies, provide the first indication of the body’s response to an infection. These antibodies are not as specific and generally are not as long lasting, so interpreting their significance requires clinical experience. 
  1. IgG antibodies are specific to a virus, such as the SARS-CoV-2 virus. Early research results suggest these antibodies can be reliably detected 14 days after a person is infected with COVID-19 or receives a COVID-19 vaccine. 

CanPath will be testing dried blood spots sampled from participants for IgG antibodies that are specific to SARS-CoV-2, the virus that causes COVID-19.  

The relationship between antibodies and immunity to infection with SARS-CoV-2 is still unknown. It is unclear whether people with antibodies are immune to re-infection or if they are still infectious to others.  

Antibodies are present for an undetermined period of time after an infection has ended. 

Serological studies, such as this one, aim to investigate these unknowns to provide a better understanding of COVID-19 and to identify how Canadians and public health officials can best respond to and manage the threat of the virus within our population. 

Can the test detect antibodies from a COVID-19 vaccine? Can the test differentiate between antibodies from COVID-19 exposure compared to antibodies from the vaccine? 

The antibody test can detect antibodies developed after receiving a COVID-19 vaccine. The results you receive will not be able to differentiate between antibodies resulting from a COVID-19 infection or a COVID-19 vaccine. Information about antibodies and the COVID-19 vaccine is evolving quickly. This study aims to help answer questions about COVID-19 antibodies and immunity. By participating in this study, you will help us answer some of these very timely questions.   

Will the antibody test detect antibodies from the new variants of COVID-19? 

Yes. The virus that causes COVID-19, SARS-CoV-2, has mutated into several different variants around the world. The lab conducting our antibody testing continues to keep an eye on the new variants detected and will adapt the test as needed to capture antibodies from variants of the virus. The CanPath test results you receive will report antibodies resulting from a previous infection of COVID-19, however will not specify which variant.   

How will my blood spot sample be used? 

The blood spot sample you provide will be tested for antibodies to COVID-19. Once the lab analysis is complete, your sample will be returned for secure storage at your regional cohort. Your sample may be used in the future by approved researchers for further health research, just like the biological samples some participants provided upon joining the study.  

Antibody Test Results

Will results of the antibody testing be returned to participants? What results will participants receive? 

Yes, the results of your COVID-19 antibody, or serological, test will be returned to you. It is expected to take up to three months to receive the test results. You will be contacted by your regional cohort.  

 You will receive one of four possible results: a positive result confirming that there are COVID-19 antibodies in your blood, a negative result indicating that there are no COVID-19 antibodies in your blood, an inconclusive result indicating that there are some COVID-19 antibodies in your blood but not enough to meet the threshold for a positive result, or a technical failure result stating that an error occurred with the sample or analysis and the lab could not determine if COVID-19 antibodies were present. 

The antibodies being tested for in this study become detectable approximately 10 to 14 days following infection or vaccination. Please consult your regular health practitioner if you have any questions about the findings from your blood spot sample. 

If you have not yet received your results regarding your immunity to COVID-19, contact your regional cohort.

When can I expect to receive the results of the antibody test of my blood spot sample? 

Study participants can expect to receive the results of the antibody test of their blood spot sample approximately three months after returning their blood spot sample to a Canada Post mailbox. 

If my sample tests positive for COVID-19 antibodies, do I need to self-isolate or get tested for COVID-19?

No.  Antibodies are not an indication of a current COVID-19 infection. If your sample tests positive for COVID-19 antibodies, this indicates that you have been infected with COVID-19 at some point in the past, or could be the result of a COVID-19 vaccine that you may have received. If you are having COVID-19 symptoms unexplained by other health conditions, please contact your regular healthcare provider.  

If you think you may have been exposed to COVID-19 and have been told to self-isolate, please wait until after this isolation period ends to participate in our study. 

If I am notified that my sample tests positive for antibodies, does this mean I no longer need to practice protective measures (i.e. physical distancing, hand-washing, wearing masks)?

At this time, it is unknown how long antibodies to COVID-19 may last, or whether having antibodies from a previous infection provides immunity to future COVID-19 infections. It is therefore important that you continue to practice protective measures (physical distancing, hand washing, wearing masks etc.) and follow public health guidelines. 

If my sample tests positive for antibodies, how long will these antibodies last? 

This is still unknown. Your participation in this study is important so we can learn more about COVID-19 infections, antibodies and immunity.

If I have been fully vaccinated for COVID-19 but my sample tests negative for antibodies, does this mean my vaccine did not work? 

The antibody test may detect antibodies developed after receiving a COVID-19 vaccine, or antibodies resulting from a previous infection of COVID-19.  If you have received a COVID-19 vaccine, you may have developed antibodies or immunity not reported by this test.

Do I still need to get vaccinated even if my results show I tested positive for COVID-19 antibodies? 

Yes. If you have tested positive for COVID-19 antibodies you should still get vaccinated. Current statistics show that antibodies, whether due to infection or vaccine, decline over time. Check out our webinar recording to learn more. 

What should I do if I have questions about my results? 

Please consult your regular health practitioner if you have any questions about the findings from your blood spot sample. Please note that these results are for research purposes only and should not change any COVID-19 precautions you are taking. 

What have been the preliminary findings from this study?

CanPath recently held a webinar by Drs. Philip Awadalla and Victoria Kirsh, where they presented preliminary findings from the COVID-19 Antibody Study. A recording of the webinar can be found here.  In brief, our findings:

  • emphasized critical age-dependent immune responses following vaccination, with weaker immune responses in older individuals
  • influenced changing guidelines on following the AstraZeneca vaccine by a second dose of an mRNA vaccine 
  • showed that stronger antibody responses were elicited by full vaccination with an mRNA vaccine compared to AstraZeneca
  • showed that antibody levels decrease with increasing time since second vaccine dose and booster shots increase antibody levels 
  • confirmed that individuals with previous SARS-CoV-2 infection elicited stronger antibody responses,   
  • showed that individuals with hematological malignancies had weaker vaccine-induced immune responses 

We also found that: 

  • the risk of infection with Omicron is 23 X higher than the Wild type 
  • 56% of current SARS-CoV-2 infections are diagnosed using rapid antigen tests 
  • ~ 49% of infections are asymptomatic 
  • 3 vaccine doses reduce the risk of infection with Omicron by 61%

How can participants use information from research findings, particularly COVID-19, to protect their personal health?  

The findings from CanPath research have been used to inform national and provincial policies and practices for general health and specific to COVID-19. Please continue to follow public health guidelines, such as getting vaccinated, wearing masks, and social distancing.

Blood Spot Sample Collection Instructions

How do I do the blood spot test? 

Instructions to complete the blood spot sample collection will be provided in the mailed kit and are linked below. 

Instructional Brochure in English860 KBDownload Instructional Brochure in French858 KBDownload

I didn’t receive/lost my test kit. Could you send me another one? 

For any questions regarding your test kit, please contact your regional cohort directly.