Geovax HIV/AIDS vaccine claims higher level of protection

GeoVax vaccine could achieve higher level of protective success than the 30% success rate achieved in Thailand

A new vaccine against HIV/AIDS infection being developed by GeoVax Labs Inc has elicited a higher response rate than the 30% success rate reported by a recently completed Phase 3 trial involving 16,000 volunteers of a candidate HIV/AIDS vaccine owned by Sanofi-Aventis and Global Solutions for Infectious Diseases.

GeoVax’ HIV/AIDs vaccine has generated higher frequencies of T cells and better quality antibody,than any other experimental vaccine candidates, the company release stated.

The recently concluded phase 3 studies using Sanofi-Aventis and Global Solutions’ HIV/AIDS vaccine in Thailand has shown “some degree of efficacy” in preventing HIV infection.

Sanofi-Aventis and Global Solutions’s HIV/AIDS vaccine trial is the first such to show prevention of infection.

Earlier, two vaccines that have failed in previous efficacy trials elicited only antibody or only T cells.

This was the first efficacy test of a vaccine that elicited both antibody and T cells and is very encouraging for the GeoVax vaccine, because Geovax vaccine generated higher frequencies of T cells and better quality antibody, according to Dr Harriet Robinson, senior vice president of Research & Development, GeoVax.

“Given what we know about the elicited responses observed in this study, and the similarities and differences between our vaccine and the Sanofi-Aventis vaccine, the GeoVax vaccine should be poised for a higher level of protective success than the 30% success rate achieved in Thailand,” noted Dr Robinson.

GeoVax’s experimental HIV/AIDS vaccine is a two component vaccine — a recombinant DNA and a recombinant modified vaccinia Ankara (MVA) – designed to stimulate both anti-HIV T cell and anti-HIV antibody immune responses.

GeoVax’s DNA and MVA vaccines are used in a prime-boost protocol in which priming is done with the DNA and boosting with the MVA.

GeoVax is also investigating a potentially simpler regimen in which MVA is used for both priming and boosting. Both the DNA and MVA express the three major proteins of the AIDS virus: Gag, Pol, and Env, and produce non-infectious virus-like-particles (VLP).

VLPs contain proteins that mimic more than half of the components of the AIDS virus, but cannot cause AIDS. This multi-protein approach is designed to elicit a broad multi-target protective T cell response. The Env protein is designed to elicit a protective antibody response against the natural form of the virus envelope glycoprotein as well as protective T cells.

GeoVax HIV/AIDS vaccine is targeted for the “clade B” sub  type of HIV-1 prevalent in the Americas, Europe and Australia.

A strong feature of GeoVax vaccines is its stability during manufacture. During development, GeoVax and its collaborators at the National Institutes of Health persevered to construct vaccines that showed solid stability under commercial manufacturing conditions, said Dr. Robinson.

GeoVax focuses on both preventative and therapeutic HIV/AIDS vaccines. GeoVax preventative version of the HIV/AIDS vaccine has advanced to a Phase 2a human clinical trial, which was initiated in February 2009 by the HIV Vaccine Trials Network (HVTN) and continues to have steadily increasing enrollment.

GeoVax plans a phase 1 human clinical trial on the therapeutic vaccine and is expected to begin this trial in the first quarter of 2010.

Atlanta-based GeoVax Labs, Inc. is a biotechnology company, established to develop, manufacture, license and commercialize human vaccines for diseases caused by HIV-1 (Human Immunodeficiency Virus) and other infectious agents. GeoVax’s AIDS vaccine technology is the subject of 20 issued or filed patent applications. GeoVax AIDS vaccines are designed for use in uninfected people to prevent Acquired Immunodeficiency Disease (AIDS), caused by the virus known as HIV-1, should the person become infected. GeoVax AIDS vaccines also may be effective as a therapeutic treatment -for people already infected with the HIV-1 virus.

GeoVax’s core AIDS vaccine technologies were developed by Dr. Harriet Robinson, Senior V.P. of Research and Development, through a collaboration of colleagues at Emory University’s Vaccine Center, the National Institutes of Health (NIH), The Centers for Disease Control and Prevention (CDC) and GeoVax.

GeoVax’s AIDS vaccines have moved forward in human clinical trials conducted by the HIV Vaccine Trials Network (HVTN) based in Seattle, Washington. The HVTN, funded through a cooperative agreement with the National Institutes of Health (NIH), is the largest worldwide clinical trials program dedicated to the development and testing of AIDS vaccines. Preclinical work enabling evaluation of GeoVax DNA and MVA vaccines was funded and supported by NIAID, which provided additional support to GeoVax AIDS vaccine development program with a $17 million IPCAVD grant awarded in late 2007.

Globally, there are about 2.5 million AIDS infections per year, most primarily involving subtypes AG, B, and C. In 2007, UNAIDS reported 1.3 million people living with AIDS in North America and 33.2 million people living with AIDS worldwide. Whereas the Thai trial was conducted with a vaccine targeted for infections endemic to Thailand.

Clade B is the predominant subtype in North America, where there are roughly 60,000 new infections each year.