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

COVID-19 vaccine effectiveness against omicron (B.1.1.529) variant infection and hospitalisation in patients taking immunosuppressive medications: a retrospective cohort study

“…Our findings regarding vaccine effectiveness in immunosuppressed patients show a substantial reduction in effectiveness relative to previous studies that looked at the delta (B.1.617.2) variant. 5 , 6 , 7 , 8 , 9 This difference is consistent with a similar reduction in the immunocompetent population, as seen in this study and in previous work. 3 , 4 The higher effectiveness observed for the mRNA-1273 vaccine compared with the BNT162b2 vaccine is also in accordance with previous findings in people who were immunocompetent.…”

“… 3 , 4 Multiple studies in patients who are immunosuppressed have shown mRNA vaccines to be effective against infection and hospitalisation due to the previously dominant delta (B.1.617.2) variant, but there are few data regarding their effectiveness against the omicron variant. 5 , 6 , 7 , 8 , 9 Patients taking immunosuppressive medications have reduced immune responses following vaccination compared with immunocompetent people, but granular data about classes of immunosuppressive medications and dose level are still scarce. 10 , 11 , 12 , 13 , 14 , 15 In addition to vaccine effectiveness, there is little knowledge on how taking immunosuppressive medications affects risk of SARS-CoV-2 infection and hospitalisation due to COVID-19.…”

SARS-CoV-2 breakthrough infections in patients with immune-mediated inflammatory diseases during the omicron dominant period

“… 7 We also observed that hospitalisation rates after SARS-CoV-2 omicron breakthrough infections were similar for most patients and healthy controls, although we found that a higher proportion of patients receiving anti-CD20 therapy were hospitalised than among those treated with other immunosuppressants. These results are consistent with a Canadian population-based study that found high effectiveness of SARS-CoV-2 vaccination against severe alpha and delta SARS-CoV-2 infections in patients with immune-mediated inflammatory diseases, 8 and a case series that found that severe SARS-CoV-2 breakthrough infections mostly occurred in patients receiving anti-CD20 therapy or mycophenolate mofetil. 9 Anti-CD20 therapy and mycophenolate mofetil severely impair antibody production after SARS-CoV-2 vaccination, even after multiple vaccine doses, 3 whereas most other immunosuppressants have no effects or less pronounced effects on humoral immunity.…”

Factors Associated with COVID-19 Breakthrough Infection in the Pre-Omicron Era Among Vaccinated Patients with Rheumatic Diseases: A Cohort Study

“…SARS-CoV-2 vaccines are highly effective against severe outcomes even among immunosuppressed patients, but breakthrough infections after vaccination have been observed. [1][2][3][4] There is particular concern among patients with systemic autoimmune rheumatic diseases (SARDs) that some may be at increased risk of breakthrough infection because of underlying immune dysregulation, immunomodulatory or immunosuppressive medications, and comorbid conditions, which may contribute to decreased vaccine efficacy and predisposition to breakthrough infection. [5][6][7][8][9] Indeed, a number of medications commonly used to treat immunemediated diseases, including anti-CD20 monoclonal antibodies, antimetabolites (e.g., methotrexate, mycophenolate), glucocorticoids, and cytokine inhibitors (e.g., TNF inhibitors), have been associated with impaired humoral response to SARS-CoV-2 and other vaccines.…”