Serological response to vaccines against SARS-CoV-2 in patients with inflammatory bowel disease.

Objective: To study the serological response (SR) and tolerability of COVID-19 vaccine in patients with inflammatory bowel disease (IBD) and its relation with IBD treatment and type of vaccine.

Methods: Observational, cross-sectional study in patients with IBD vaccinated against COVID-19 without known previous infection. SR was analyzed by the determination of IgG antibodies against the S1 subunit. Safety was studied using a questionnaire to identify adverse effects (AE).

Results: 280 patients with IBD were included. Type of vaccines: Comirnaty® 68.8%; Spikevax® 10.8%, Vaxzevria® 18.3%, Ad26.COV2-S® 2.2%. 51.3% had AE, being 100% mild. 65% developed IgG antibodies after vaccination. The SR was higher for vaccines with mRNA technology (100% Spikevax®, 68.5% Comirnaty®) compared to those based on adenovirus vector (38.0% Vaxzevria®, 33.3% Ad26.COV2-S®) (P<.001). In the multivariate analysis, SR was related to age (<60 years; OR: 3.8, 95% CI 1.9-7.0; P<.001). The SR in patients with aminosalicylates was 65.4%, 61.4% with immunosuppressants, 65.8% with anti-TNF, and 68.7% with non-anti-TNF biologicals (P=.9).

Conclusions: One third of patients with IBD did not develop antibodies with the initial vaccination against SARS-CoV-2. The SR to vaccines based on mRNA technology was higher, and it was related to age (higher in younger patients). Immunosuppressants and biologicals did not decrease SR. More than half of the patients presented AD, being mild in all cases.