A Pilot Study Comparing the Immunogenicity of Fendrix vs. Double-dose Engerix B in HIV-infected Non-responders to Standard Hepatitis B Vaccination Courses

To compare the immunological responses in HIV-infected non-responders to standard hepatitis B vaccination courses to immunization with either double-dose Engerix B or Fendrix: 1. Investigators will measure the proportion of individuals seroconverting with Hepatitis B surface antibody titres of \>100 (and ≥10) IU/ml at 8 weeks after the immunisation course, as well as the durability of this response at 1 year following the completion of the course. The primary aim will be to provide some preliminary data from a head to head study of these two approaches with which to power a larger multi-centre randomized controlled trial. 2. Investigators will define the magnitude and quality of the Hepatitis B-specific CD4+ T-cell response following vaccination, thus obtaining key immunological data to fill the knowledge gap in T-cell responses to Hepatitis B vaccination, required to support the rationale design of future multi-centre, randomized study comparing vaccination strategies in HIV-infected non-responders to standard Hepatitis B vaccine courses. The research is original. There is only one published study to date looking at the efficacy of double-dose Engerix B in HIV-infected non-responders to standard courses1. There is currently anecdotal experience of the use of Fendrix in this group from the Investigators cohort and others. There are no head-to-head comparisons of these two strategies.