P354 Immunological response to vaccination against SARS-COV-2 infection in Inflammatory Bowel Disease patients under immunosuppressive therapy: should we prioritize an additional booster injection?

Macedo Silva, V.(1,2,3);Lima Capela, T.(1,2,3);Freitas, M.(1,2,3);Cúrdia Gonçalves, T.(1,2,3);Boal Carvalho, P.(1,2,3);Dias de Castro, F.(1,2,3);Moreira, M.J.(1,2,3);Cotter, J.(1,2,3);

(1)Hospital da Senhora da Oliveira, Gastroenterology Department, Creixomil- Guimarães, Portugal;(2)School of Medicine- University of Minho, Life and Health Sciences Research Institute ICVS, Braga, Portugal;(3)PT Government Associate Laboratory, ICVS/3B’s, Braga / Guimarães, Portugal;


The severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection may lead to the development of the novel coronavirus disease 2019 (COVID-19). Currently, little to no data is available regarding safety and efficacy of SARS-COV-2 vaccination in Inflammatory Bowel Disease (IBD) patients, which may present differences between subgroups, as these patients may exhibit impaired innate and adaptive immune system responses. Lower immunological response could, in this specific population, require an additional booster injection.


We conducted a prospective study including adult patients with Crohn’s disease (CD) and Ulcerative Colitis (UC) who have undergone complete vaccination against SARS-COV-2 infection with BioNTech® vaccine. Patients with previous SARS-COV-2 infection were excluded. Medical data regarding age, sex, IBD classification and current medication for IBD were collected.
A control group with healthy individuals matched for age and sex was also analyzed.
Blood samples were collected 30 days after complete vaccination to quantify IgG antibody titers for SARS-COV-2 in both groups (IBD and non-IBD).


Our final sample included 81 IBD and 32 non-IBD patients, 55 (48.7%) of them females, with a mean age of 40.2±13.0 years. From the IBD patients, 58(71.6%) had CD and 23(28.4%) had UC.
IBD patients had significantly lower anti-SARS-COV-2 IgG levels when compared to the control group (8950±9366 vs 14834±11679 AU/mL; p=0.003).
Regarding IBD medication, significant lower levels of SARS-COV-2 IgG antibodies when compared to control patients were found in patients under thiopurines (9074±9779 AU/mL; p=0.011); methotrexate (1987±2568 AU/mL; p=0.002); infliximab (7208±7276 AU/mL; p=0.001); and corticosteroids (1065±933 AU/mL; p=0.001). Additionally, patients under combined therapy (infliximab plus thiopurines) presented with significantly lower antibodies titers when compared to patients treated with thiopurines in monotherapy (8130±11048 vs 10563±5680 AU/mL; p=0.039).
No significant differences were found in IBD patients under salicylates (10195±7371 AU/mL; p=0.226); adalimumab (15644±21467 AU/mL; p=0.336); vedolizumab (10464±9087 AU/mL; p=0.286) and ustekinumab (11366±10016 AU/mL; p=0.390).


IBD patients presented with significantly lower anti-SARS-COV-2 IgG levels 1 month after complete vaccination against SARS-COV-2 infection compared to healthy controls. Thiopurines, methotrexate, infliximab and corticosteroid treatment were associated with significantly lower antibodies levels. These findings may express the benefit of an additional booster injection in this population.