Safety of an Oral HIV Vaccine in HIV Uninfected Volunteers

Overview

This study will test the safety of and immune response to an oral HIV vaccine in healthy volunteers. The vaccine in this study uses a weakened bacterium called Salmonella typhi to deliver an HIV gene into the body through the mouth. The body then produces an HIV protein from the gene; this protein stimulates an anti-HIV immune response. The vaccine contains only one of the many substances that HIV needs to make more copies of itself, so the vaccine itself cannot cause HIV or AIDS.

The transmission of HIV-1 by both sexual and parenteral routes makes it likely that a successful preventive vaccine against this virus will need to induce protective immunity in both mucosal and systemic compartments. The long-term objective of this program is to develop an HIV-1 vaccine that elicits protective immunity in both the mucosal and systemic compartments. The study will evaluate the safety and immunogenicity of an oral recombinant Salmonella typhi HIV-1 gp120 vaccine (SCBaL/M9) in healthy human volunteers. This will be the first study in volunteers to use an intracellular bacterium to deliver a recombinant vector vaccine mucosally. The study will also develop an Env immunogen that elicits a broader spectrum of neutralizing antibodies than gp120 and that can be delivered by Salmonella typhi or as a soluble protein immunogen. This is a Phase I dose-escalation study of two vaccine components that will be combined in a larger prime-boost protocol should the desired safety endpoints be obtained. Both components use a conformationally constrained gp120 that expresses epitopes recognized by broadly neutralizing antibodies. The priming immunogen will be the conformationally constrained gp120 gene delivered orally by live attenuated Salmonella typhi. The boosting immunogen will be a soluble subunit protein comprised solely of the conformationally constrained gp120. All participants in this study will receive the vaccine. Participants will be randomized to different vaccine doses. Participants will have eight study visits over 20 weeks. Study visits will include brief medical interview, physical exam, blood and urine tests, and counseling on avoiding HIV infection and pregnancy. Participants will be tested for HIV infection 3 times during the study.

Conditions

Interventions

Eligibility

Locations (1)

Outcomes

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