A phase I/II trial to compare the immunogenicity and safety of three DNA C prime followed by one NYVAC C boost to two DNA C prime followed by two NYVAC C boost

The primary endpoints are immunogenicity and safety.

The primary immunogenicity parameter will be the presence of CD8/CD4+ T-cell responses defined according to internationally agreed criteria for evaluation of interferon-gamma (IFNƒ×) Enzyme-Linked Immunosorbent SPOT (ELISPOT) assays:
1. In response to env peptide plus at least one of the gag, pol, nef peptide pools
2. At weeks 26 and 28

The primary safety parameters will be graded and are:
1. Grade 3 or above local adverse event (pain, cutaneous reactions including induration)
2. Grade 3 or above systemic adverse event (temperature, chills, headache, nausea, vomiting, malaise and myalgia)
3. Grade 3 or above other clinical or laboratory adverse event confirmed at examination or on repeat testing, respectively.
4. Any event attributable to vaccine leading to discontinuation of the immunisation regimen.

Secondary immunogenicity and safety end-point information will be collected on all participants on the following:
1. Cellular responses:
1.1. CD8/CD4+ T cell mean IFNƒ× Spot Forming Units (SFU) per million cells across the peptide pools at weeks 26 and 28
1.2. CD8/CD4+ T cell mean Spot Forming Units (SFU) per million cells across the peptide pools at any week following the first immunisation including weeks 48 and 72
1.3. Mean proportion of CD4/CD8+ T cells producing IL-2 and/or IFN-ƒ× following ex-vivo stimulation with HIV-1 peptide pools at weeks 26 and 28, 48 and 72
1.4. Number of different epitopes that can be characterised
2. Antibody responses: precise assays to be determined at a later stage, but prior to unblinding of laboratory personnel
3. All grade 1 and 2 adverse events
4. All events including those considered unrelated to vaccine