Humoral Immunogenicity of mRNA COVID-19 Vaccines Among Patients With Inflammatory Bowel Disease and Healthy Controls.

Introduction: Patients with inflammatory bowel disease (IBD) on immune-modifying therapies may have a lower vaccine response to certain vaccines. The aim of our study was to evaluate humoral immunogenicity of mRNA coronavirus disease 2019 (COVID-19) vaccines among patients with IBD and healthy controls (HCs).

Methods: We performed a prospective study to evaluate humoral immunogenicity among patients with IBD and HCs after completion of mRNA COVID-19 vaccines.

Results: One hundred twenty-two patients with IBD and 60 HCs were enrolled. All HCs and 97% of patients with IBD developed antibodies. Antibody concentrations were lower in patients with IBD compared with those in HCs (median 31 vs 118 μg/mL; P < 0.001). Those who received the mRNA-1273 (Moderna) COVID-19 (median 38; interquartile range [IQR] 24-75 vs μg/mL) had higher antibody concentrations compared with those who received the Pfizer-BNT vaccine series (median 22; IQR 11-42 μg/mL; P < 0.001). Patients on immune-modifying therapy (median 26; IQR 13-50 μg/mL) had lower antibody concentrations compared with those who were on no treatment, aminosalicylates, or vedolizumab (median 59; IQR 31-75 μg/mL; P = 0.003).

Discussion: Almost all patients with IBD in our study mounted an antibody response. Future studies are needed in evaluating sustained humoral immunity and the impact of booster dosing in patients with IBD.