Encouraging HIV/AIDS Vaccine Trial Results Support GeoVax Labs Inc. Strategy

ATLANTA, Sept. 24 /PRNewswire-FirstCall/ -- GeoVax Labs, Inc. (the "Company"), an Atlanta-based, biopharmaceutical company developing human vaccines for HIV/AIDS (HIV-1, Human Immunodeficiency Virus), was pleased to hear the announcement today of partial success in the recently completed Phase 3 trial in Thailand of a candidate HIV/AIDS vaccine owned by Sanofi-Aventis and Global Solutions for Infectious Diseases. The completed study represents the first HIV/AIDS vaccine trial to show prevention of infection.

"The partial success of this trial is very important to the GeoVax vaccine, because the vaccine tested in Thailand, like the GeoVax vaccine, was designed to elicit both T cells and antibody," said Dr. Harriet Robinson, Senior Vice President of Research & Development. "The 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 our vaccine generates higher frequencies of T cells and better quality antibody. 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.

The Technology

GeoVax's unique two component vaccine, a recombinant DNA and a recombinant modified vaccinia Ankara (MVA), is 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. These particles 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.

HIV affects the entire globe and comes in a variety of subtypes. Clade B is the predominant subtype in North America, where there are roughly 60,000 new infections each year. 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; the GeoVax vaccine is targeted for the "clade B" type of HIV-1 prevalent in the Americas, Europe and Australia.

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.

Safe Harbor Statement

All statements in this news release, not statements of historical fact, are forward-looking statements. These statements are based on expectations and assumptions on the date of this press release and are subject to numerous risks and uncertainties which could cause actual results to differ materially from those described in the forward-looking statements. Risks and uncertainties include, but are not limited to, whether: GeoVax can develop and manufacture these vaccines with the desired characteristics in a timely manner, GeoVax's vaccines will be safe for human use, GeoVax's vaccines will effectively prevent AIDS in humans, vaccines will receive regulatory approvals necessary to be licensed and marketed, GeoVax raises required capital to complete vaccine development, there is development of competitive products that may be more effective or easier to use than GeoVax's products, and other factors over which GeoVax has no control. GeoVax assumes no obligation to update these forward-looking statements, and does not intend to do so. Certain matters discussed in this news release are forward-looking statements involving certain risks and uncertainties including, without limitation, risks detailed in the Company's Securities and Exchange Commission filings and reports.

GeoVax Labs, Inc.