Safety of and Immune Response to a Prime-Boost Vaccine Regimen in HIV-Uninfected Vaccine-Naive Adults

HIV Infections Clinical Trial

Official title: A Phase 2a Clinical Trial to Evaluate the Safety and Immunogenicity of a Prime-boost Vaccine Regimen of pGA2/JS7 DNA and MVA/HIV62, in Healthy, HIV Uninfected Vaccinia-naive Adult Participants

Status Completed

Clinical Trial Summary

The purpose of this study is to evaluate the safety of and immune response to a two-vaccine regimen in healthy, HIV-uninfected adults who have never received an HIV preventive vaccine before.

Clinical Trial Description

Some of the first HIV vaccines were designed to trigger neutralizing antibody responses as a way to prevent HIV infection. Unfortunately, the first versions of these vaccines were not able to achieve their desired response. An alternative strategy to the antibody approach is the stimulation of HIV-specific CD8 T-lymphocyte (CTL) responses. CTL responses were previously demonstrated to play an important role in the control of simian immunodeficiency virus (SIV), the HIV equivalent seen in rhesus macaque monkeys. Additionally, other studies suggest CTLs play an important role in viral control during chronic infection. Based on this information, several groups have shifted their focus to the development of CTL-based vaccines, some of which have entered advanced clinical trials.

A DNA/rMVA vaccine strategy is structured to bring about both T-cell and antibody responses. The primary vaccination is DNA based and will express only HIV proteins as a way to produce an HIV-focused immune response. An rMVA vaccine strategy expresses both HIV and MVA proteins and may amplify the focused response of a DNA vaccination. Participants in this study will receive either a combined DNA/rMVA vaccine strategy, in which they receive both types of vaccines; an rMVA vaccine strategy, in which they receive only the rMVA vaccine; or a placebo. The DNA and rMVA are physically two different vaccinations given at separate times, but in the DNA/rMVA group, they will be used together to make up one preventive regimen. Both vaccine components express noninfectious virus-like particles.

This study is a multicenter, randomized study that is conducted in two parts and comprised of five groups. In all groups, participants will receive four injections. In Part A, Groups 1 and 2 will be compared. In Group 1, participants will receive two shots of the DNA vaccine and two shots of the rMVA vaccine. In Group 2, participants will receive four placebo injections. In Part B, Groups 3, 4, and 5 will be compared. In Group 3, the combination vaccine strategy will be used again; in Group 4, a single-vaccine strategy of three injections of the rMVA vaccine and one injection of placebo will be given; and in Group 5, participants will again receive four placebo injections. The study will last for a total of 12 months for participants, including enrollment and follow-up. ;

Related Conditions & MeSH terms

• HIV Infections

• NCT number: NCT00820846
• Study type: Interventional
• Source: National Institute of Allergy and Infectious Diseases (NIAID)
• Status: Completed
• Phase: Phase 2
• Start date: January 2009
• Completion date: September 2014