A Multicenter, Randomized, Placebo-Controlled, Double-Blind Trial to Evaluate the Safety and Immunogenicity of the Therion Recombinant Vaccinia-HIV-1 IIIB ENV/GAG/POL Vaccine (TCB-3B) and MN RGP 120/HIV-1 In Alum.
Condition: HIV Infections
MeSH terms: Vaccinia
Study type: Interventional

Summary: 
      To evaluate the safety of administering Therion Recombinant Vaccinia-HIV-1 IIIB env/gag/pol
      Vaccine (TBC-3B) vaccinations to vaccinia-naive individuals. To evaluate the immunogenicity
      of priming with TBC-3B by the scarification, intradermal, and subcutaneous routes, followed
      by booster immunization of MN rgp120 HIV-1. To compare the immunogenicity of priming with
      TBC-3B in vaccinia-naive individuals to vaccinia-immune individuals.

      In prior trials evaluating alternative methods of vaccine administration, scarification has
      been found to be an imprecise method of administration and allows only 1.0 - 2.5 microliters
      of immunogen to be given. Since it is not feasible to produce vaccine at concentrations
      higher than 10 to the 10th pfu/ml, this method limits the maximum deliverable dose.
      Intradermal and subcutaneous injection routes allow larger volumes of vaccinia to be given,
      i.e.: up to 200 microliters intradermally and up to 100 ml subcutaneously. In the present
      study, the initial priming dose will be the same administered by all 3 methods; however, the
      second priming dose administered at 2 months intradermally and subcutaneously will be 2 logs
      higher in order to achieve boosting of immune responses, particularly to gag and pol
      components of TBC-3B.
    

Detailed description: 
      In prior trials evaluating alternative methods of vaccine administration, scarification has
      been found to be an imprecise method of administration and allows only 1.0 - 2.5 microliters
      of immunogen to be given. Since it is not feasible to produce vaccine at concentrations
      higher than 10 to the 10th pfu/ml, this method limits the maximum deliverable dose.
      Intradermal and subcutaneous injection routes allow larger volumes of vaccinia to be given,
      i.e.: up to 200 microliters intradermally and up to 100 ml subcutaneously. In the present
      study, the initial priming dose will be the same administered by all 3 methods; however, the
      second priming dose administered at 2 months intradermally and subcutaneously will be 2 logs
      higher in order to achieve boosting of immune responses, particularly to gag and pol
      components of TBC-3B.

      After volunteers are recruited, screened and enrolled in the study, they will be randomized
      to group C, D, or E. Each group will enroll 10 patients and 2 controls. The placebo control
      for TBC-3B will be standard vaccinia vaccination administered at doses no higher than that
      administered by scarification; the placebo control for MN rgp120 will be alum. Group C will
      receive undiluted TBC-3B by scarification, at months 0 and 2. Group D will receive diluted
      TBC-3B intradermally at month 0 and undiluted TBC-3B at month 2. Group E will receive diluted
      TBC-3B subcutaneously at month 0 and undiluted TBC-3B at month 2. At months 8 and 12 all
      groups will receive MN rgp 120/HIV-1 in alum intramuscularly.
    

Intervention name(s): MN rgp120/HIV-1; TBC-3B Vaccine
Intervention type(s): Biological; Biological
Masking: Double
Primary purpose: Prevention
Keywords: Vaccines, Synthetic; Vaccinia Virus; Placebos; HIV-1; AIDS Vaccines; HIV Seronegativity; Genes, env; Genes, pol; Genes, gag; HIV Preventive Vaccine