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Immunogenicity of COVID-19 Vaccines in Long Term Care (CovidAB)

Status: Currently Recruiting

Study Doctors:

  • Dr. Anne Claude Gingras, Sinai Health System
  • Dr. Allison McGeer, Sinai Health System
  • Dr. Jen Gommerman, University of Toronto
  • Dr. Sharon Straus, Unity Health Toronto
  • Dr. Mario Ostrowski, Unity Health

What is the purpose of this study?

The purpose of this study is to better understand how vaccines work against COVID-19. We wish to describe:
    1. how much antibody people make when they are vaccinated against the virus that causes COVID-19
    2. how long the antibody lasts
    3. whether people who have had COVID-19 before make more antibody, or have antibody that lasts longer
    4. whether residents of long term care homes make less antibody than other adults
    5. whether antibodies can be detected in saliva of individuals vaccinated against COVID19 , how it compares to antibody levels detected in blood, and how long does it last in the saliva

Who can participate?

Anyone who works, or is an essential caregiver at a long term care home in south central Ontario, and who is planning to be vaccinated against COVID-19.

What are participants being asked to do?

If you agree to participate in this study, you will be asked to:

  • Allow research staff to ask you a few questions about any underlying medical conditions you may have and any regular medications you are taking, whether or not you have had COVID-19 and when, and which COVID vaccine you have received or will receive and when.
  • Notify the study staff if you have or test positive for COVID-19 during the study.
  • Let the study know when you have received or plan to receive the Covid19 vaccination.
  • Submit blood samples  to the study in one of two ways:
  • Option 1  (for LTCH staff only)
    • a. Have blood taken (25 mls) before your first dose of vaccine (or up to 7 days after your first dose of the vaccine), and at 12 months after your second vaccine dose, and 5 mls of blood taken 2-4 weeks and 6 months after your second dose. You can have your blood drawn by appointment at your LTC home or your nearest Lifelabs phlebotomy office. If you received your first dose of vaccine more than a week ago, you will have blood taken (25mls) 2-4 weeks and 12 months after your second dose of vaccine, and 5 mls of blood drawn 6 months after your second dose.
    • b.  Provide a saliva sample via salivette  (i.e., a swab that you hold in your mouth) at the same time as you provide blood samples).
  • Option 2  (for LTCH staff or caregivers)
    • a. Self-collect dried blood spots 4 times:  just before you get your first vaccine dose, just before you get your second, 2 weeks after you get your second, and 4 months after you get your second. Dried blood spots are collected exactly the same way that people with diabetes measure their blood sugar. A lancet uses a very short needle to automatically poke your finger so that it bleeds a small amount. You collect the blood spots on a special piece of filter paper.  Antibodies against COVID-19 are measured in this blood. 
    • b.Have one regular venous  blood sample (2 teaspoons) taken 2 weeks after you get your second dose of vaccine.  You can have your blood drawn by study or Life Labs staff at your LTC home or at a convenient LifeLabs location . No saliva samples are required for this option.
  • Allow study staff to contact you after this study is over to ask if you would be willing to consider being part of other studies of COVID19.


Participation is voluntary. You can agree to help with all or only some of these things. You can also agree to be part of the study now, but change your mind later.

What should I do if I might be interested in being part of the study?

If you are interested in the study, please call the study office at 416-586-4800 ext. 2767, or email the study office at covidAB@sinaihealth.ca.  Contacting the study does not commit you to participating, it just allows you to learn more about the study and to decide whether or not you want to participate.