Utility of a Third Heplisav-B Dose in Patients with Inflammatory Bowel Disease without Immunity Following Two-Dose Heplisav-B Vaccination.

OBJECTIVES: Hepatitis B virus (HBV) vaccination is recommended in patients with inflammatory bowel disease (IBD). Although the two-dose Heplisav-B vaccine has proven effective, more than 20% of patients with IBD do not seroconvert. We prospectively evaluated the effectiveness of a third Heplisav-B dose in patients with IBD lacking HBV immunity despite two-dose vaccination.

METHODS: Adults with IBD who had received two-dose Heplisav-B vaccination between 2018-2023 were identified. Seroconversion was defined as hepatitis B surface antibody (HBsAb) >10 IU/L measured at >4 weeks following vaccination. Patients who did not seroconvert were prospectively offered a third Heplisav-B dose, followed by repeat HBsAb measurement. Demographic, clinical, medication, and vaccination data was compared between those who did and did not seroconvert.

RESULTS: Of 192 patients identified, 71.9% (138/192) seroconverted following two-dose Heplisav-B vaccination. The 54 patients (28.1%) who did not seroconvert were more likely to be male, have diabetes, chronic kidney disease, or elevated Charlson Comorbidity Index. Of the 54 patients, 30 (55.6%) elected to receive a third Heplisav-B dose, with 56.7% (17/30) achieving seroconversion (median HBsAb titer 376 IU/L, IQR 47-1000 IU/L) despite a median inter-vaccination time of 416 days (IQR 90.8-667.8). No differences were noted between patients who did versus did not seroconvert following third dose vaccination.

CONCLUSION: In patients with IBD lacking HBV immunity despite two-dose Heplisav-B vaccination, administration of a third dose resulted in a 56.7% seroconversion rate. Our results suggest that administration of an additional Heplisav-B dose may be an effective strategy in patients lacking immunity despite primary two-dose vaccination.