Safety & Immunogenicity of HIV Vaccines in Healthy Kenyan Adults

The study is part of a long-term aim to develop an effective HIV-1 vaccine and will evaluate safety and immunogenicity of vaccines focusing T cell responses on the conserved region of the HIV-1 proteome. The vaccines used are pSG2.HIVconsv DNA (D), MVA.HIVconsv (M) and Ad35-GRIN (A), delivered in regimens AM, DDDAM and DeDeDeAM, where e indicates electroporation.

The main objectives of this study are to determine the vaccines' safety and immunogenicity in an African population, and further strengthen the vaccine trial capacity in the South. HIV-CORE 004 is a double blind, placebo controlled randomized Phase I/IIa study designed to evaluate the safety and immunogenicity of different delivery regimens using three novel HIV-1 vaccines pSG2.HIVconsv DNA (D) with and without electroporation (e), adenovirus Ad35-GRIN (A) and poxvirus MVA.HIVconsv (M) administered by intramuscular needle injection in heterologous prime-boost regimens. 72 healthy, low-risk, HIV-1-uninfected adult volunteers in Nairobi will be randomly assigned to one of three groups, AM, DDDAM and DeDeDeAM each containing 20 vaccinees and 4 placebo recipients. Firstly, this study aims to evaluate the safety and tolerability of the vaccines pSG2.HIVconsv DNA (D) with and without electroporation (e), adenovirus Ad35-GRIN (A) and poxvirus MVA.HIVconsv (M). Secondly, we shall determine the effect of electroporation during DNA priming on the frequency, durability and/or quality of T cell responses (DDDAM vs DeDeDeAM). Thirdly, we shall determine whether priming with three DNA vaccinations with or without electroporation affects the frequency, durability and/or quality of T cell responses to the HIVconsv immunogen compared to that seen in the AM regimen (AM vs DDDAM/DeDeDeAM). As this is the first study of the combined HIVconsv vaccines in an African population, of the pSG2.HIVconsv DNA with electroporation, and the combination of the two HIVconsv vaccines with Ad35-GRIN, this trial has been designed as a pilot study to compare different vector combinations. The sample sizes will only allow detection of large response differences between volunteers in the three groups, thus, yielding data that are primarily descriptive.