MONTREAL, July 21, 2021 – Because of their expertise, clinician-researchers Hélène Decaluwe, Elie Haddad and Fabien Touzot and their colleagues from the Immunology-Rheumatology Department at CHU Sainte-Justine will be participating in the national VISID project led at the Ottawa Hospital and at the University of Ottawa in terms of pediatrics, to understand how well do COVID-19 vaccines work in people with inherited and medication-related immune deficiencies.

People with inherited primary immune deficiencies have a greater risk of developing severe COVID-19. People with multiple sclerosis, arthritis and other immune-mediated diseases may also be at risk because medications for these conditions often suppress the immune system.

“Fortunately, children with primary immune deficiencies seem less affected by severe forms of COVID-19 than adults. However, they may be less able to acquire good protection after vaccination against the virus,” indicates Dr. Hélène Decaluwe, clinician-researcher in pediatric immunology at CHU Sainte-Justine and associate professor in the Department of Pediatrics at the University of Montreal.

Under the direction of Dr. Juthaporn Cowan, infectious disease physician and associate scientist at the Ottawa Hospital and assistant professor at the University of Ottawa, the research team aims to recruit 460 participants with inherited or medication-related immune deficiencies from twelve sites across Canada (in Ottawa, Montreal, Toronto, Halifax, Winnipeg, Edmonton, Calgary and Vancouver). The researchers also hope to recruit healthy individuals over 12 who have not yet been vaccinated, but plan to be, as a control group.

The researchers will collect blood samples from the participants to study the body’s response to COVID-19 vaccines, including antibody levels and T cell response. Participants will also fill out questionnaires and be followed by health care professionals to assess any vaccine side effects.

“Our study will provide crucial data to help us protect people with immune deficiencies against COVID-19,” said Dr. Cowan. “It will also help us learn more about which compartment of the immune system is essential in the COVID-19 vaccine response, so that better vaccines can be developed in the future.”

"CHU Sainte-Justine's contribution to clinical and basic research in the field of pediatric immune diseases is a major on an international scale. By participating in this study, it will be possible for us to understand the impact of vaccination specific in this population and thus help to push our expertise even further in the care and monitoring of young patients with primary immune deficiencies,” explains Dr. Decaluwe.

Dr. Decaluwe is also a co-principal investigator for the PSI Foundation-funded PITCH Project which aims to understand protective immunity against COVID-19 in children.

Antibodies develop after an acute infection with SARS-CoV-2, but antibody levels can decline rapidly in some individuals, especially if the infection is mild or asymptomatic. New data suggests that long-term immunity may also be provided by T cells, which are essential for controlling and eradicating viral infections as well as immune memory.

There is currently very little data on the immune response of T cells in children infected with COVID-19. In the present study, the research team will measure the response of T cells 2, 6 and 12 months after confirmed infection with COVID-19.

The participants are also part of another joint study (the PATCH study) examining the antibody response to COVID-19 and the research team wants to compare the response of T cells and antibodies at similar time points over a period of one year. The data obtained will be able to inform public health policies and optimal COVID-19 vaccine coverage targets for adults and children.

“You should know that it is the duration of immunity to SARS-CoV-2 that will determine the course of this pandemic,” concludes Dr. Decaluwe.

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