Posttransplant HBV Vaccine Compliance, Seroprotection, and Kinetics of Hepatitis B Surface Antibody in Thoracic Organ Transplant Recipients.

Introduction: Vaccination is crucial to the thoracic solid organ transplant (SOT) population to reduce vaccine‐preventable infection. However, data on posttransplant hepatitis B virus (HBV) vaccination compliance and vaccine‐induced seroprotection are lacking. Methods: We conducted a retrospective study of adult thoracic organ (heart and lung) transplant recipients at Mayo Clinic sites in Minnesota, Arizona, and Florida between January 2018 and August 2023. Recombivax HB was used before 2020, and Heplisav‐B was preferred after 2020. Recipients with posttransplant hepatitis B surface antibody (HBsAb) < 10 IU/L were eligible for the HBV vaccine. HBV seroprotection was defined as an HBsAb ≥ 10 IU/L. Results: A total of 1116 recipients were evaluated, all of whom underwent posttransplant HBsAb testing. Of these, 751 (67%) had an HBsAb level < 10 IU/L and were eligible for posttransplant HBV vaccination. Of the eligible recipients, 117 (16%) completed the HBV vaccine series during the study period. Among these 117 recipients, 40 (34%) had their HBsAb levels rechecked after completing the vaccine series, with a seroprotection rate of 37.5% (15/40). There was no statistically significant difference in the seroprotection rates between Heplisav‐B and Recombivax HB vaccines (39% [13/33] vs. 29% [2/7]; p = 0.691). In addition, HBsAb levels were lowest at week 2 but rebounded at week 4 posttransplant and pretransplant HBsAb levels of ≥100 IU/L ensured 5‐year seroprotection. Conclusion: Suboptimal compliance with HBV vaccination and poor vaccine‐induced seroprotection occur in thoracic organ transplant recipients, regardless of the vaccine used. These findings underscore the necessity of enhancing vaccination strategies for SOT recipients. [ABSTRACT FROM AUTHOR]