Immunogenicity of High Dose Influenza Vaccine for Patients with Inflammatory Bowel Disease on Anti-TNF Monotherapy: A Randomized Clinical Trial

Background: Patients with inflammatory bowel disease (IBD) on anti-tumor necrosis factor alpha (TNF) agents may have lower immune response to the influenza vaccine. We aimed to evaluate the immunogenicity of the high dose (HD) vs standard dose (SD) influenza vaccine in patients with IBD on anti-TNF monotherapy. Methods: We performed a randomized clinical trial at a single academic center evaluating the immunogenicity of the HD vs SD influenza vaccine in patients with IBD on anti-TNF monotherapy. Influenza antibody concentration was measured at immunization, at 2 to 4 weeks postimmunization, and at 6 months. Results: Sixty-nine patients with IBD were recruited into the study, 40 on anti-TNF monotherapy, and 19 on vedolizumab, along with 20 healthy controls (HC). Patients with IBD receiving the HD influenza vaccine had significantly higher H3N2 postimmunization antibodies compared with those who received the SD influenza vaccine (160 [interquartile range 80 to 320] vs 80 [interquartile range 40 to 160]; P = 0.003). The H1N1 postimmunization levels were not significantly higher in the HD influenza vaccine (320 [interquartile range 150 to 320] vs 160 [interquartile range 80 to 320]; P = 0.18). Patients with IBD receiving the HD influenza vaccine and those on vedolizumab who received SD had equivalent antibody concentrations to HC (H1N1 P = 0.85; H3N2 P = 0.23; B/Victoria P = 0.20 and H1N1 P = 0.46; H3N2 P = 0.21; B/Victoria P = 1.00, respectively). Conclusions: Patients with IBD on anti-TNF monotherapy receiving the HD influenza vaccine had significantly higher postimmunization antibody levels compared with SD vaccine.