Serological Response to BNT162b2 and ChAdOx1 nCoV-19 Vaccines in Patients with Inflammatory Bowel Disease on Biologic Therapies; A Multi-Center Prospective Study

Introduction Immunogenicity of SARS-CoV-2 vaccines in patients with inflammatory bowel disease (IBD) on biologics are not well studied. The goal of this study is to measure serological response to BNT162b2 and ChAdOx1 nCoV-19 vaccines in patients with IBD receiving different biologic therapies. Method We performed a multi-center prospective study between August 1st, 2021, and September 15th, 2021. We measured seropositivity of SARS-CoV2 antibodies, SARS-CoV-2 IgG and neutralizing antibody concentrations, in patients with IBD receiving biologic therapies between 4-10 weeks after second dose or 3-6 weeks after first dose of vaccination with BNT162b2 or ChAdOx1 nCoV-19 vaccines. Results There were 126 patients enrolled (mean age, 31 years; 60% male; 71% Crohns disease, 29% ulcerative colitis). 92 patients were vaccinated with BNT162b2 vaccine (73%) and 34 patients with ChAdOx1 nCoV-19 vaccine (27%). The proportion of patients who achieved positive anti-SARS-CoV-2 IgG antibody levels after receiving 2 doses of the vaccine in patients treated with infliximab and adalimumab were 44 out of 59 patients (74.5%) and 13 out of 16 patients (81.2%), respectively. Whereas the proportion of patients who achieved positive anti-SARS-CoV-2 IgG antibody levels after receiving two doses of the vaccine in patients treated with ustekinumab and vedolizumab were 100% and 92.8%, respectively. In patients receiving infliximab and adalimumab, the proportion of patients who had positive anti-SARS-CoV-2 neutralizing antibody levels after two-dose vaccination was 40 out of 59 patients (67.7%) and 14 out 16 patients (87.5%), respectively. Whereas the proportions of patients who had positive anti-SARS-CoV-2 neutralizing antibody levels were 12 out of 13 patients (92.3%) and 13 out of 14 patients (92.8%) in patients receiving ustekinumab and vedolizumab. Conclusion: The majority of patients with IBD on infliximab, adalimumab, and vedolizumab seroconverted after two doses of SARS-CoV-2 vaccination. All patients on ustekinumab seroconverted after two doses of SARS-CoV-2 vaccine. BNT162b2 and ChAdOx1 nCoV-19 SARS-CoV-2 are both likely to be effective after two doses in patients with IBD on biologics. A follow up larger studies are needed to evaluate if decay of antibodies occurs over time.