This is a summary, written by members of the CITF Secretariat, of:

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

The results and/or conclusions contained in the research do not necessarily reflect the views of all CITF members.

New findings from the CITF-funded SUCCEED project, published in The Lancet Rheumatology, indicate that two doses of mRNA vaccines were 79 to 89% effective at preventing SARS-CoV-2 infection in individuals living with immune-mediated inflammatory diseases in Ontario. While vaccine effectiveness started to wane two months after the second dose, it rebounded after a third dose. The study, which collected data from almost all individuals living with these conditions in the province, took place between March 1 and November 22, 2021, when the Alpha and Delta variants of concern were circulating. Two-dose vaccine effectiveness against severe COVID-19 varied between 92 and 97%. SUCCEED is headed by Dr. Sasha Bernatsky from the Research Institute of the McGill University Health Centre, along with Drs. Jessica Widdifield and Jeff Kwong based at IC/ES.

This study focused on four major immune-mediated inflammatory diseases: rheumatoid arthritis, ankylosing spondylitis (a type of arthritis that affects the spine), psoriasis (a skin condition), and inflammatory bowel disease (also known as IBD). Individuals living with these conditions are often on immunosuppressant therapies, which may compromise their immune system and make them more susceptible to severe disease from COVID-19.

Key findings:

  • Test positivity rates (i.e., the number of positive tests divided by the total number of individuals tested) among people belonging to the four immune-mediated inflammatory disease groups were (in descending order): 3,089 of 47,199 (5%) individuals with psoriasis, 476 of 7,863 (6.1%) individuals with ankylosing spondylitis, 2,127 of 36,145 (5.9%) individuals with rheumatoid arthritis, and 1,702 of 31,311 (5.4%) individuals with IBD.
  • Across all four disease groups, positive cases were more likely to occur in younger individuals (roughly < 50 years old) and those residing in lower-income neighbourhoods compared to higher-income neighbourhoods.
  • Adjusted mRNA vaccine effectiveness seven days after the second dose against any SARS-CoV-2 infection among the disease groups were as follows: 89% for those with ankylosing spondylitis, 84% for those with psoriasis, 83% for those with rheumatoid arthritis, and 79% among those living with IBD.
  • Across all four disease groups, vaccine effectiveness against infection after one and two doses was higher for those who received Moderna Spikevax compared to those who received Pfizer-BioNTech Comirnaty.
  • Adjusted two-dose mRNA vaccine effectiveness against severe COVID-19 outcomes (i.e., hospitalization and/or death attributed to the virus) among the four disease groups were as follows: 92% for those with rheumatoid arthritis and with psoriasis, 94% for those living with IBD, and 97% among those with ankylosing spondylitis.
  • Vaccine effectiveness against infection seven days after receipt of a third dose ranged from 76% to 96%. Third doses became available for this population in September 2021.

All SARS-CoV-2 diagnostic PCR tests performed on individuals aged 16 and older in Ontario belonging to the above four disease groups were identified.

These findings stem from the CITF-funded Safety immUnogenicity of Covid-19 vaCcines in systEmic immunE mediated inflammatory Diseases (SUCCEED) project, led by Dr. Bernatsky.

It should be noted that the study predates the emergence of the Omicron variant in Canada.

Read the news release