Response to COVID-19 Vaccination in Patients with Inflammatory Bowel Disease on Biological Treatment

Background: The antibody response to coronavirus disease 2019 (COVID-19) vaccination in patients with inflammatory bowel disease (IBD) on biological drugs is still unclear. Aim: To determine the anti-SARS-CoV-2 spike 1 (anti-S1-IgG) response rate and antibody levels following a complete COVID-19 vaccination cycle in patients with IBD on biological treatment. Methods: We assessed antibody response to COVID-19 in consecutive patients with IBD on biological drugs and without prior exposure to COVID-19. Sera were prospectively collected at baseline and at 21 days (T1), 42 days (T2), and 3 months (T3) after the first vaccine dose. Results: Among the 42 patients included in the study, the overall response rate at T3 was 97.6%, with no difference across the various biological drugs. After the first dose (T1), the response rate was higher in patients receiving anti-tumour necrosis factor (TNF) compared to patients treated with other biologics (p = 0.031). Among the responders, the anti-S1 levels were not significantly different among the various biological drugs at all study timepoints. Concomitant corticosteroids and disease activity had no impact on the response rate at all study timepoints. No unexpected side events were observed. Discussion: The antibody response to vaccination against COVID-19 in patients with IBD on biological drugs is optimal, independently of their mechanism of action. Patients treated with anti-TNF seem to have an earlier response to vaccination, while concomitant low-dose corticosteroids and disease activity does not seem to impact response. This information can be used to program vaccination and inform patients.