Serological Responses Support COVID-19 Vaccine Recommendations in Patients With IBD

IBD, Inflammatory bowel disease
Investigators evaluated serological responses to COVID-19 vaccines in patients with irritable bowel disease.

Among patients with inflammatory bowel disease (IBD) using biological therapies, investigators found serological responses with 100% seropositivity after 2-dose Pfizer-BioNTech and NIH-Moderna COVID-19 vaccination, as reported in Gastroenterology.

The COVID-19 in Therapeutic Infusion (CiTI) study sought to assess the serological responses to COVID-19 vaccination with the SARS-CoV-2 spike (S) mRNA BNT162b2 (Pfizer-BioNTech) and mRNA-1273 (NIH-Moderna) vaccines in patients with IBD.

Patients self-reported at least 1 vaccination appointment from December 14, 2020, to February 12, 2021. Control group participants included 14 fully vaccinated health care workers (HCW) without IBD who had 1 blood draw and 29 vaccinated healthy volunteers (PICR cohort) without IBD who had serial blood draws after vaccination. The study authors also evaluated antibody testing results from 21 patients with SARS-CoV-2 infections for comparison with naturally generated antibodies.

A total of 48 patients with IBD were included in the analysis (23 with Crohn disease and 25 with ulcerative colitis). Most patients (85.4%) were taking biologics at the time of vaccination. The vaccinated HCWs (mean age, 35.2 years; 50% female) and PICR cohort participants (mean age, 31.5 years; 37.9% female) were younger compared against the patients with IBD (mean age, 49 years; 52% female; P =.016 and P <.0001, respectively).

Participants received either the Pfizer-BioNTech (IBD n=23; HCW n=11; PICR n=20) or NIH-Moderna (IBD n=25; HCW n=3; PICR n=9) vaccines. Among the IBD patients, 26 completed 2 doses, and 22 completed 1 dose. All HCW control participants and 26 (89.7%) PICR control participants completed 2 doses. The study authors screened the samples for pre-existing antibodies with anti-nucleocapsid testing.

All patients with IBD who completed the 2-dose vaccine schedules had positive anti– receptor binding domain (RBD) tests, of whom 22 (84.6%) achieved index levels qualifying for convalescent plasma donation. In addition, 2 patients with IBD and previous SARS-CoV-2 infection had high index values after 1 vaccine dose, well above values from natural SARS-CoV-2 infection, noted the researchers.

When comparing anti-S Immunoglobulin G (IgG) levels in patients with IBD against those of the PICR and HCW groups, similar titers at all timepoints were observed. Multiple linear regression analyses found no association between infusion timing and antibody response in patients who received 2 vaccine doses.

Of the 26 patients who completed the 2 COVID-19 vaccine doses, 8 were receiving tumor necrosis factor (TNF) antagonist monotherapy, 12 were receiving vedolizumab monotherapy, 2 were receiving ustekinumab, and 4 were taking no medication. Anti-TNFs were associated with lower anti-RBD total Ig only (P =.0299), while vedolizumab was associated with lower anti-RBD total Ig (P =.0069), anti-RBD IgG (P =.045), and anti-S IgG (P =.0043) compared with HCW control participants.

Study limitations include the small sample size, single-center design, and differences in time to blood collections.

The investigators stated, “…this study brings a reassuring message to IBD patients and health care practitioners.” They continued, “…our results support the consensus recommendation for IBD patients to receive COVID-19 vaccines when available.”

Disclosures: Some of the study authors declared affiliations with pharmaceutical companies. Please see the original reference for a full list of disclosures.


Wong S-Y, Dixon R, Pazos VM, et al. Serological response to mRNA COVID-19 vaccines in IBD patients receiving biological therapies. Gastroenterol. Published online April 19, 2021. doi: 10.1053/j.gastro.2021.04.025