Optimizing hepatitis B virus seroprotection in thoracic organ transplantation: The role of HepB-CpG (Heplisav-B) vaccination schedule

Introduction: Heplisav-B, a CpG-adjuvanted recombinant hepatitis B virus (HBV) vaccine, has a higher seroprotection rate and immunogenicity than the conventional HBV vaccine. This study aimed to identify the predictors of HBV seroprotection post-transplantation in thoracic organ transplant recipients who received Heplisav-B.

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 2020 and August 2023. Patients who completed Heplisav-B series were classified into three strategies: strategy A (completed 2 doses of Heplisav-B pre-transplantation with achieved seroprotection pre-transplantation), strategy B (received first dose of Heplisav-B pre-transplantation and second dose of Heplisav-B post-transplantation), and strategy C (completed 2 doses of Heplisav-B post-transplantation). HBV seroprotection was defined as HBsAb ≥10 IU/L.

Results: A total of 154 thoracic organ transplant recipients completed Heplisav-B vaccine series. Post-transplant seroprotection was highest in strategy A, followed by strategy B and strategy C (54/76 [71 %] vs. 18/39 [46 %] vs. 14/39 [36 %]; p < 0.001). Multivariate logistic regression analysis identified two independent factors predicting lack of HBV seroprotection post-transplantation; both were related to Heplisav-B schedule: strategy B (adjusted odds ratio [aOR], 2.482; 95 % confidence interval [CI] 1.085 5.679; p = 0.031), and strategy C (aOR 4.963; 95 % CI 2.106 11.697; p < 0.001).

Conclusion: The vaccine schedule significantly predicts HBV seroprotection in adult thoracic organ transplant recipients. Our data supports the recommendation that pre-transplantation Heplisav-B to achieve HBsAb ≥10 IU/L is the optimal vaccination schedule to maintain an HBsAb level of ≥10 IU/L post-transplantation. Further studies are needed to determine whether this observation can be replicated in non-thoracic organ transplant recipients or pediatric populations.