Safety of and Immune Response to a Prime-Boost Vaccine Regimen in HIV-Uninfected Vaccine-Naive Adults
Condition: HIV Infections
MeSH terms: HIV Infections
Study type: Interventional
Phase: Phase 2

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.
    

Detailed 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.
    

Intervention name(s): pGA2/JS7 DNA vaccine; Placebo; MVA/HIV62 vaccine
Intervention type(s): Biological; Biological; Biological
Intervention description(s): 1 mL of pGA2/JS7 DNA vaccine; 1 mL of sodium chloride for injection; 1 mL of recombinant modified vaccinia Ankara/HIV clade B gag-pol-env (MVA/HIV62)
Intervention MeSH terms: Vaccines
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Participant, Care Provider)
Primary purpose: Prevention
Keywords: HIV Seronegativity; HIV Preventive Vaccine