Antibody, not cellular, immune Responses to SARS-CoV-2 vaccination outperform infection in inflammatory bowel disease patients

Following the successful development of the first vaccines to protect against SARS-CoV-2 infection, the International Organization for the Study of Inflammatory Bowel Disease (IOIBD) recommended full vaccination of all patients with inflammatory bowel disease (IBD) already early in the pandemic.1 Subsequent studies have reported the effects of immunosuppressive medications on immune responses to SARS-CoV-2 infection and vaccination in patients with IBD. The most consistent findings are of reduced serological responses in patients on infliximab and an uncoupling of cellular and humoral responses.2–5 Although previous studies assessed aspects of the immune response in IBD, a direct longitudinal comparison of immunity induced by primary SARS-CoV-2 infection compared with vaccination in patients with IBD has not been reported. As part of the ICARUS-IBD study at the Icahn School of Medicine at Mount Sinai, patients with IBD were followed from early in the pandemic (May 2020) prior to vaccine development through March 2022 when full vaccination schedules, including booster doses, were available. We prospectively obtained clinical data, serum, and peripheral blood mononuclear cells (PBMCs; Supplementary Figure 1). This biobank allows the first detailed examination of the relative immune response to naturally acquired infection compared with vaccination-induced immunity