Montreal, May 3, 2022 – New findings, published in The Lancet Rheumatology, suggest that people with immune-mediated inflammatory diseases (IMIDs) respond well to vaccination and that the COVID-19 vaccines in Canada are highly effective in protecting them against hospitalization from COVID-19. The results of this study are highly pertinent for people living with rheumatoid arthritis, ankylosing spondylitis (a type of arthritis that characteristically affects the spine), psoriasis (a skin condition), and inflammatory bowel disease (IBD) – the four patient populations included in the study, supported by the Government of Canada, through its COVID-19 Immunity Task Force (CITF).

Conducted over the period between March 1 and November 22, 2021, the study shows that mRNA vaccines were highly effective (92 to 97 per cent) against severe COVID-19 outcomes (defined as admission to hospital or death due to COVID-19) for individuals living with IMIDs during this period. These individuals often take immunosuppressant therapies, which may compromise their immune system. Thus, they may be more susceptible to severe disease from COVID-19.

Although there was some slight waning in effectiveness against infection over time, vaccination remained highly effective even beyond 120 days after the second dose, and rebounded upon receipt of a third dose.

“The effectiveness of vaccines for Canadians living with immune-mediated inflammatory diseases has not been thoroughly investigated before, primarily due to them being excluded from COVID-19 vaccine clinical trials,” says Dr. Jessica Widdifield, lead author of the study and a scientist in the Holland Bone and Joint Program at Sunnybrook Health Sciences Centre. “Our encouraging findings begin to give a clearer picture of vaccine effectiveness in those with IMIDs.”

“Many of these patients have tried numerous treatments to achieve good disease control and regain function,” explains Dr. Sasha Bernatsky, senior author of the study and a professor in the Divisions of Rheumatology and Clinical Epidemiology, Department of Medicine at the Research Institute of McGill University Health Centre. “At the same time, the drugs patients require to manage their conditions may also increase their susceptibility to infection. These findings, up to November 2021, demonstrate that it is possible for individuals with IMID to achieve adequate protection via COVID vaccination.”

Across all four disease groups, vaccine effectiveness against infection was found to be higher for those who received Moderna’s Spikevax COVID-19 vaccine compared to those who received Pfizer-BioNTech’s Comirnaty.

“In Canada, more than seven million people over the age of 16 live with an immune-mediated inflammatory disease,” says Dr. Catherine Hankins, Co-Chair of the COVID-19 Immunity Task Force. “We funded this research in order to generate evidence that will assist regulators, doctors, and patients in making evidence-based decisions regarding COVID vaccination, not only in the general population, but in populations with specific health issues, such as those with an IMID. All members of society have the right to be adequately protected.”

The study team collected results of SARS-CoV-2 diagnostic PCR tests performed on individuals aged 16 and older living with IMIDs in Ontario. Records of vaccination, hospitalization, and death due to COVID-19 were also collected for everyone. The study took place when the Alpha and Delta variants of concern were circulating, thus the authors of the study argue that it is important to re-evaluate these findings in the context of Omicron and future waves.

The study is a collaboration of scientists from Sunnybrook Health Science Centre, IC/ES, and the Research Institute of the McGill University Health Centre.

More information:

Widdifield J, Kwong JC, Chen S, Eder L, Benchimol EI, Kaplan GG, Hitchon C, Aviña-Zubieta JA, Lacaille D, Chung H, Bernatsky S. Vaccine effectiveness against SARS-CoV-2 infection and severe outcomes among individuals with immune-mediated inflammatory diseases tested between March 1 and Nov 22, 2021, in Ontario, Canada: a population-based analysis. The Lancet Rheumatology. 2022 Apr 14. Doi: 10.1016/S2665-9913(22)00096-0

 About Sunnybrook Health Sciences Centre

Sunnybrook Health Sciences Centre is inventing the future of health care for the 1.3 million patients the hospital cares for each year through the dedication of its more than 10,000 staff and volunteers. An internationally recognized leader in research and education and a full affiliation with the University of Toronto distinguishes Sunnybrook as one of Canada’s premier academic health sciences centres. Sunnybrook specializes in caring for high-risk pregnancies, critically ill newborns and adults, offering specialized rehabilitation, and treating and preventing cancer, cardiovascular disease, neurological and psychiatric disorders, orthopaedic and arthritic conditions and traumatic injuries. The hospital also has a unique and national leading program for the care of Canada’s war veterans.

 About the Research Institute of the McGill University Health Centre (RI-MUHC)

The Research Institute of the McGill University Health Centre (RI-MUHC) is a world-renowned biomedical and healthcare research centre. The institute, which is affiliated with the Faculty of Medicine of McGill University, is the research arm of the McGill University Health Centre (MUHC) – an academic health centre located in Montreal, Canada, that has a mandate to focus on complex care within its community. The RI-MUHC supports over 450 researchers and around 1,200 research trainees devoted to a broad spectrum of fundamental, clinical and health outcomes research at the Glen and the Montreal General Hospital sites of the MUHC. Its research facilities offer a dynamic multidisciplinary environment that fosters collaboration and leverages discovery aimed at improving the health of individual patients across their lifespan. The RI-MUHC is supported in part by the Fonds de recherche du Québec – Santé (FRQS).

 About the COVID-19 Immunity Task Force

 The Government of Canada established the COVID-19 Immunity Task Force (CITF) in late April 2020 to catalyze, support, fund, and harmonize research on SARS-CoV-2 immunity for federal, provincial, and territorial decision-makers in their efforts to protect Canadians and minimize the impact of the COVID-19. To date, the CITF has supported over 100 studies across Canada that are generating critical insights on the levels, trends, nature, and duration of immunity arising from SARS-CoV-2 infection and COVID-19 vaccination. The CITF is overseen by a Leadership Group of volunteers that includes leading scientists and policymakers from across Canada. The Task Force and its Secretariat work closely with a range of partners, including governments, public health agencies, institutions, health organizations, research teams, other task forces, engaging communities and stakeholders.

Media contacts:

Sunnybrook Health Sciences Centre
Samantha Sexton

Fabienne Landry
Cell: +1.514.812.7722

COVID-19 Immunity Task Force
Rebecca Burns
Cell: +1.438.871.8763

The views expressed herein do not necessarily represent the views of the Public Health Agency of Canada.