PURPOSE OF REVIEW
The purpose of review is to provide an overview of the Pox-Protein Public Private Partnership (P5) and highlight the progress of the P5 program, including an upcoming HIV vaccine efficacy trial in South Africa.
The RV144 Thai vaccine efficacy trial was the first to demonstrate that an HIV-1 vaccine can prevent HIV acquisition. The P5 vaccine regimen uses an ALVAC prime and protein boost modeled after the RV144 vaccine and adapted for the subtype C virus predominant in the southern African region. This regimen was recently tested in the HIV Vaccine Trials Network 100 phase 1/2a study in South Africa. Based on prospectively defined immunogenicity thresholds, criteria were met to support the launch of an efficacy study in late 2016. The aim of this phase IIb/III trial will be to improve upon the results of RV144, with increased and more durable vaccine efficacy, to accelerate the potential licensure of a preventive vaccine in southern Africa.
The planned P5 efficacy trial, HIV Vaccine Trials Network 702, is designed to test and prospectively define correlates of protection, if efficacious. A vaccine with modest efficacy, vaccine efficacy at least 50%, could have substantial public health impact and significantly decrease the incidence of new infections in heavily burdened areas of the world.