Impact of BNT162b2 mRNA Vaccination on the Development of Short and Long-Term Vaccine-Related Adverse Events in Inflammatory Bowel Disease: A Multi-Center Prospective Study.

Introduction: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination has been effective in protecting against severe COVID-19 infections and related mortality. It is recommended for all individuals including patients with inflammatory bowel disease (IBD). However, safety data are lacking in this group of patients. Therefore, we aim to evaluate the short- and long-term vaccine related adverse events (AEs) in patients with IBD. Methods: This is a prospective, observational cohort study investigating short- and long-term AEs related to the BNT162b2 vaccine in patients with IBD (study group) after the first and second dose compared to healthy participants (control group). Patients were recruited at the time of attendance to the clinic or infusion rooms. Short term (<3 weeks) localized and systemic AEs were assessed Results: A total of 408 patients answered the questionnaires, 204 patients in each group, the study and control group. No serious adverse events were reported in either the study or the control group after the first or the second dose. Participants in the control group reported more frequent pain at the injection site than those in the study group after the first dose [58 (57%) vs. 38 (37%) respectively, Conclusion: The BNT162b2 vaccine is safe in patients with IBD. No severe or long-term adverse events were reported in our study. The frequency of local and systemic adverse events after the second dose was generally higher among healthy participants compared to patients with IBD. Further studies including a larger cohort with a longer follow-up duration are needed to assess for possible rare adverse events.