SARS-CoV-2 Vaccination in IBD: Past Lessons, Current Evidence, and Future Challenges.

Since the beginning of the pandemic, patients with inflammatory bowel diseases [IBD] have been considered at high risk for infection and complications of COVID-19. IBD patients and patients taking immunosuppressive therapy were excluded from clinical phase III vaccine trials, complicating the assessment of effectiveness of these new vaccines. From past experience we know that adapted vaccination strategies may be appropriate in some IBD patients to optimise immunogenicity. We review current evidence on SARS-CoV-2 vaccination relevant to IBD patients, including immune responses from humoral to cellular, emerging data on new variants, and off-label vaccination schemes. We also identify clinical and scientific knowledge gaps that can be translated into both large-scale population-based studies and targeted vaccine studies to describe the precise immune responses induced by SARS-CoV-2 vaccines in IBD patients. We strongly endorse the recommendation of vaccinating IBD patients to ensure maximal protection from COVID-19 both for the individual and the community.