Evaluation of Titer-Proven Response Rates of Pediatric Hepatitis B-Combination Vaccines in Adult Hematopoietic Cell Transplant Recipients.

Background: Patients who have undergone hematopoietic cell transplant (HCT) should be revaccinated with common childhood vaccines due to loss of immunity. It is common for transplant centers to encourage adherence by administering combination vaccines to alleviate high vaccine burden. A combination product containing pediatric doses of hepatitis B surface antigen (10 µg) is commonly utilized, although limited data are available on response post-HCT.

Methods: The primary objective of this study was to determine the efficacy of a low-dose, combination hepatitis B vaccine by assessing titer-proven response rates. The secondary objective was to characterize factors that influence non-response. Post-HCT patients were included in this analysis if they received all three post-HCT doses of low-dose DTaP-HepB-IPV with a subsequently documented hepatitis B titer result. Following the successful completion of the protocol, patients were considered responders to the vaccine if they had measurable titers ≥10 mIU/mL.

Results: Thirty-nine patients met inclusion criteria. A serologic response to the vaccine series was observed in 21 of the 39 patients (54%). Allogeneic HCT recipients were found to have a response rate of 76%, whereas autologous recipients were less likely to respond (response rate 36%, p = 0.02).

Conclusion: An appropriate response to a low-dose, combination hepatitis B vaccine was observed in allogeneic HCT recipients. Autologous response rates are low, though this finding is consistent with prior literature.