Anti-SARS-CoV-2 Vaccination and Antibody Response in Patients With Inflammatory Bowel Disease on Immune-modifying Therapy: Prospective Single-Tertiary Study

BACKGROUND Patients with inflammatory bowel disease (IBD) on immune-modifying treatment could be at an increased risk for severe coronavirus disease 2019 (COVID-19); thus, data on the efficacy and safety of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) vaccines are essential. We conducted a prospective study of IBD patients vaccinated with BNT162b2, CX-024414, and ChAdOx1 nCoV-19 vaccines. The aim was to evaluate the rate and magnitude of seroconversion, assess the effect of different immune-modifying treatment modalities on the magnitude of anti-SARS-CoV-2 IgG antibody levels, and analyze the impact of anti-SARS-CoV-2 vaccination on the inflammatory biomarkers of IBD. METHODS The study included 602 IBD patients and 168 immunocompetent health care workers serving as controls. Serum anti-SARS-CoV-2 IgG antibodies were measured by chemiluminescent microparticle immunoassay before the vaccination and 8 weeks after the vaccination. RESULTS Of IBD patients, 82.2% were receiving biological treatment: most of them were treated with antitumor necrosis factor (TNF)-α inhibitors (48.5%), and just under half of them were treated with concomitant thiopurines or methotrexate, followed by vedolizumab (18.6%) and ustekinumab (15.1%). Only 8.1% of patients were on 5-aminosalicylates, and a minority (2.2%) were treatment-free. The postvaccine seropositivity rate among IBD patients and controls was 97.8% vs 100%. Median anti-SARS-CoV-2 IgG levels were lower among IBD recipients of ChAdOx1 nCoV-19 compared with 2 other vaccines (P < .0001) and control ChAdOx1 nCoV-19 recipients (P=.01). No correlation was found between serum trough levels and anti-SARS-CoV-2 IgG concentrations for any of the biological drugs used. The TNF-α inhibitors with concomitant immunosuppressive treatment but no other treatment modalities were associated with a lower postvaccination antibody response (P < .0001). When evaluating the laboratory activity of IBD by C-reactive protein and fecal calprotectin levels, no significant differences were found before the vaccination and 8 weeks after its completion. CONCLUSIONS Our findings warrant particular attention to the anti-SARS-CoV-2 vaccination of IBD patients treated with TNF-α inhibitors with concomitant immunomodulators and show the priority of mRNA vaccines in this specific group of patients.