Effects of Different Biological Therapies on S1/S2 Antibody Response to SARS-CoV-2 Vaccination in a Cohort of Patients with Inflammatory Bowel Disease

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection has affected the entire planet. The objectives of our study were to compare responses to the vaccine (Pfizer-Biontech COMIRNATY) in a population of patients with intestinal bowel syndrome undergoing different biological therapies or conventional therapy. The study recruited 390 patients who received the first vaccination dose during the dedicated vaccination campaign for inflammatory bowel disease (IBD) patients. The inclusion criteria were a diagnosis of CD or UC and complete vaccination with the Pfizer–BioNTech COVID-19 (Comirnaty) vaccine. The exclusion criteria were other significant diseases or important therapies under way or contraindications to vaccination according to the European drug surveillance recommendations. Linear rank models were run to assess the association between the different therapies and S1/S2 antibodies at three different times. The models showed that in patients with IBD receiving Vedolizumab a significant increase in mean IgG levels was observed, independently of other therapies and confounding factors (β: 57.45, 95% CI 19.62 to 19.00). This study confirmed the complete antibody response to vaccination against COVID-19 in patients with IBD undergoing biological therapy—particularly Vedolizumab treatment—but also a reduced immune response due to concomitant steroid therapy.