BACKGROUND Observational data and non-human primate challenge studies suggest that cell-mediated immune responses might provide control of HIV replication. The Step Study directly assessed the efficacy of a cell-mediated immunity vaccine to protect against HIV-1 infection or change in early plasma HIV-1 levels. METHODS We undertook a double-blind, phase II, test-of-concept study at 34 sites i...

To assess associations between the timing of hepatitis B virus (HBV) immunization relative to human immunodeficiency virus (HIV) diagnosis and vaccine effectiveness, US Military HIV Natural History Study cohort participants without HBV infection at the time of HIV diagnosis were grouped by vaccination status, retrospectively followed from HIV diagnosis for incident HBV infection, and compared u...

Procedures must be developed to ensure that valid informed consent is obtained from participants in HIV vaccine efficacy trials. A prototype informed consent process was evaluated among 4,892 persons at high risk for HIV infection in the HIV Network for Prevention Trials Vaccine Preparedness Study (VPS), a prospective cohort study of HIV seroincidence in eight U.S. metropolitan areas. Twenty pe...

BACKGROUND It is important for public health and within the HIV vaccine development field to understand the potential population level impact of an HIV vaccine of partial efficacy--both in preventing infection and in reducing viral load in vaccinated individuals who become infected--in the context of a realistic future implementation scenario in resource limited settings. METHODS An individua...

Many efforts have been made in the worldwide quest for a prophylactic HIV vaccine to end the AIDS pandemic, but none has yet succeeded. The lessons learned have repeatedly informed us that the traditional or conventional approaches directly using the pathogens or subunits will not be sufficient for an effective HIV/AIDS vaccine. Recent advances in structure-based technology have shown some prom...

A broadly effective HIV-1 vaccine would greatly contribute towards pathway deepens our understanding of the level of somatic prevention of the 2.1 million new HIV-1 infections estimated to occur annually. Six HIV-1 vaccine efficacy trials in humans have thus far been conducted. Whereas most vaccines showed no efficacy in preventing from HIV-1 infection – and two actually increased infection rat...

The Step study of a recombinant adenovirus serotype 5 (Ad5)-based human immunodeficiency virus type 1 (HIV-1) vaccine revealed an increased risk of HIV-1 acquisition in vaccinees who were Ad5 seropositive at baseline. We therefore investigated whether preexisting Ad seropositivity to 7 different Ad serotypes was associated with increased risk of HIV-1 infection in 3 HIV-1 vaccine efficacy trial...

In April 2006, the National Institute of Allergy and Infectious Disease (NIAID)-funded HIV Vaccine Trials Network and the NIAID Division of AIDS sponsored a workshop at which nonhuman primate (NHP) researchers and clinical trial scientists with HIV vaccine research expertise discussed how to more effectively use NHPs for evaluating HIV-1 vaccine candidates. This workshop precipitated a broad di...

Five doses of inactivated Mycobacterium vaccae vaccine were administered intradermally to 22 human immunodeficiency virus (HIV)-infected patients (11 bacille Calmette-Guérin [BCG]-positive and 11 BCG-negative) in Zambia whose CD4 lymphocyte counts were >/=200 cells/mm(3). HIV viral load and lymphocyte proliferation responses were compared for vaccine recipients and 22 HIV-infected control patie...

The efficacy of an HIV vaccine to prevent infection is likely to depend on the genetic variation of the exposing virus. This paper addresses the problem of using data on the HIV sequences that infect vaccine efficacy trial participants to (1) test for vaccine efficacy more powerfully than procedures that ignore the sequence data and (2) evaluate the dependence of vaccine efficacy on the diverge...