Clinical Trial: Immunogenicity of Double‐Dose Versus Standard‐Dose of Hepatitis B Virus Vaccine in Inflammatory Bowel Disease

Background Immunogenic response to hepatitis B virus (HBV) vaccine in patients with inflammatory bowel disease (IBD) is variable and often suboptimal. Aim To compare the immunogenicity of standard‐dose (20 μg) vs. double‐dose (40 μg) HBV vaccination in patients with IBD. Methods We randomised patients with IBD 1:1 to receive standard‐ or double‐dose HBV vaccine at 0, 1 and 6 months. Anti‐HBs titres were measured 1 month after the third dose. The primary outcome was an adequate immune response (AIR; anti‐HBs titre > 10 IU/L). Secondary outcomes included an effective immune response (EIR; anti‐HBs titre > 100 IU/L) and seroconversion stratified by disease activity. Results We randomised 45 patients to the standard‐dose and 43 to the double‐dose. Overall, 63 patients (71.6%) achieved AIR, and 51 (57.9%) achieved EIR. Both AIR (88.4% vs. 55.6%, p = 0.001) and EIR (69.8% vs. 46.7%, p = 0.028) rates were significantly higher with the double‐dose. Among patients receiving immunosuppressive therapy, double‐dose vaccination demonstrated significantly higher AIR (87.5% vs. 45.2%, p < 0.001) and EIR (65.6% vs. 35.5%, p = 0.017), while differences were not significant in those without immunosuppression. On multivariable analysis, predictors of AIR included double‐dose vaccination (odds ratio [OR] 11.63; 95% confidence interval [CI] 2.63–51.46) and anti‐TNFs (OR 0.03; 95% CI 0.002–0.6). Double‐dose vaccination was also associated with higher odds of achieving EIR (OR 3.52; 95% CI 1.04–11.92). Conclusions Double‐dose HBV vaccination significantly improved AIR and EIR over standard‐dose. These findings support a double‐dose strategy to optimize seroconversion in patients with IBD, especially those receiving immunosuppressive therapy.