Fendrix® compared to Engerix® in HIV-infected patients nonresponding to initial- and re-vaccination schedule.

Background: In HIV-infected patients, the immunogenicity of hepatitis B vaccines is impaired. In this randomised controlled study (RCT), we investigated the effect of Fendrix® versus double-dose Engerix® vaccination in previously non-responsive HIV-infected subjects.

Methods: Patients included those who were HIV-infected and non-responders to a primary (single-dose hepatitis B (HBV) vaccination) and a subsequent double-dose HBV revaccination schedule. Subjects were randomised 1:1 to receive Fendrix® (t = 0, 4, 8, 24 weeks) or double-dose Engerix® (t = 0, 4, 24 weeks) vaccinations. Primary efficacy, defined as anti-HBs response ≥ 10 IU/l, was evaluated at week 28 in both study arms.

Results: A subset of 48 patients non-responsive to HBV vaccination was selected, from a cohort of patients at our institution, who underwent HBV vaccination unsuccessfully either in a previous RCT or through standard care. The anti-HBs ≥ 10 IU/l response rate at week 28 in the Fendrix® arm and the Engerix® arm were 85.7% and 65.0%, respectively (p = 0.09). There was no significant difference between the two used vaccine types in the anti-HBs levels reached. In our institution, the overall response rate after initial standard-dose vaccination schedule and double-dose revaccination in our cohort was 75%. In this study, combining the effects of Fendrix and Engerix resulted in a 75% response rate in the 25% remaining non-responders on initial and double-dose revaccination series. This yielded an absolute 19% increase and an overall response to HBV vaccination in HIV-infected patients of around 94% in our cohort.

Conclusion: These results together, suggest that continuing HBV vaccination in non-responders to a first course of single-dose vaccine and a double-dose revaccination scheme is worth the effort. No superiority of one of the investigated hepatitis B vaccines was shown in this cohort but an appropriate number of patients needed to achieve reliable answers was not achieved.