Poxvirus vector-based HIV vaccines.
OBJECTIVE
In this review, we will provide the scientific rationale for the use of poxvirus vectors in the field of HIV vaccines, the immunological profile of the vaccine-induced immune responses, an update on the current use of poxvirus vector-based vaccines in HIV vaccine clinical trials, and the development of new modified poxvirus vectors with improved immunological profile.


RESULTS
An Ad5-HIV vaccine was tested in a phase IIb clinical trial (known as the Step trial). Vaccinations in the Step trial were discontinued because the vaccine did not show any effect on acquisition of infection and on viral load. After the disappointing failure of the Step trial, the field of HIV vaccine has regained enthusiasm and vigour due to the promising protective effect observed in the phase III efficacy trial (known as RV-144) performed in Thailand which has tested a poxvirus-gp120 combination.


CONCLUSIONS
The RV-144 phase III has provided for the first time evidence that an HIV vaccine can prevent HIV infection. The results from the RV-144 trial are providing the scientific rationale for the future development of the HIV vaccine field and for designing future efficacy trials.
Division of Immunology and Allergy, Centre Hospitalier Universitaire Vaudois, University of Lausanne, Switzerland. Giuseppe.Pantaleo@chuv.ch
Giuseppe
G
Pantaleo
Mariano
M
Esteban
Bertram
B
Jacobs
Jim
J
Tartaglia
D016915:AIDS Vaccines / Q000235:genetics / Q000276:immunology*; D002986:Clinical Trials as Topic; D005822:Genetic Vectors; D015699:HIV Envelope Protein gp120 / Q000235:genetics / Q000276:immunology*; D015658:HIV Infections / Q000517:prevention & control*; D015497:HIV-1 / Q000235:genetics / Q000276:immunology*; D006801:Humans; D013785:Thailand; D014614:Vaccines, Synthetic / Q000235:genetics / Q000276:immunology; D014616:Vaccinia virus / Q000235:genetics*
D016915:AIDS Vaccines; D015699:HIV Envelope Protein gp120; D014614:Vaccines, Synthetic