In this study the safety, tolerability and immunogenicity of a recombinant MVA-BN® expressing CTL and HTL epitopes of HIV-1 (MVA-mBN32) vs. the vector control MVA-BN® in 30 HIV-infected subjects will be examined. This will include a full analysis of CD4+ T helper cells and CD8+ CTL responses to these epitopes, to establish the potential of such a homologous prime-boost vaccine approach to induce a broad cell-mediated response to different HIV antigens.