LAUSR

Abstract Background The safety of a third dose of SARS-CoV-2 mRNA vaccination in patients with inflammatory bowel disease is unknown. Methods We compared symptoms following a third SARS-CoV-2 mRNA vaccine dose with symptoms after the second dose in IBD. Results The study group included 594 patients (70% female, 58% BNT162b2). Overall, 41% reported symptoms after a third dose. Symptom frequency and severity were lower after the third dose relative to the second dose for every organ system, except for gastrointestinal symptoms which were marginally worse. Conclusion The frequency and severity of symptoms after a third mRNA vaccine dose are generally similar or milder than after a second dose for most organ systems.