GeoVax Phase 2a Clinical Trial Completes Enrollment

Participants Demonstrating Neutralizing Activity that Blocks Infection

ATLANTA, Oct. 3, 2011 /PRNewswire/ -- GeoVax Labs, Inc. (OTCQB/OTCBB: GOVX), an Atlanta-based biopharmaceutical firm developing vaccines to prevent and fight Human Immunodeficiency Virus (HIV) infections, announced today the completion of enrollment for a Phase 2a clinical trial testing its HIV/AIDS vaccine. The vaccine is being developed for use in uninfected people to prevent infection should they be exposed to the virus. The trial, designated HVTN 205, is being conducted by the HIV Vaccines Trials Network (HVTN), which is funded by the National Institute of Allergy and Infectious Diseases, part of the National Institutes of Health. A total of 299 participants are enrolled in HVTN 205.

GeoVax also announced the unblinding of data for neutralizing antibody (Ab) responses in part 1 of HVTN 205 – showing elicitation of unexpectedly high response rates of neutralizing antibody for tier 2 isolates of HIV-1.  Of 46 tested vaccine recipients, 50% responded with neutralizing activity for tier 2 clade B isolate RHPA; and 26% with neutralizing antibody for tier 2 clade B isolate SC22.3C2. Neutralizing antibodies can block virus from infecting cells by binding to regions of the virus that mediate entry into cells. The elicitation of neutralizing antibody for tier 2 viruses is an important result because tier 2 viruses represent viruses that undergo the most frequent transmission from an infected person to an uninfected person. A new highly sensitive test was used for conducting neutralization tests, which were done at the HVTN laboratories at Duke University.

"Elicitation of neutralizing antibody is a much sought goal for an HIV/AIDS vaccine," said Harriet Robinson, Ph.D., Chief Scientific Officer of GeoVax. "The field has been trying to achieve this goal by re-engineering the HIV envelope protein that mediates entry into cells. Our vaccines use natural forms of the HIV envelope to raise antibody. We are extremely pleased that our natural form of the HIV envelope protein can elicit neutralizing Ab for tier 2 viruses."

"The completion of enrollment for our phase 2a trial is an important milestone," said Robert  McNally, Ph.D., GeoVax's President and CEO. "We now look forward to completion of the inoculations and the unblinding of safety and immunogenicity results for the entire trial."

Patient enrollment for HVTN 205 was conducted at 11 clinical sites in North America and two sites in South America.

About GeoVax Labs, Inc.

GeoVax is a biotechnology company developing human vaccines for diseases caused by HIV (Human Immunodeficiency Virus – that leads to AIDS) and other infectious agents. Our goals include developing HIV/AIDS vaccines for global markets, overseeing the manufacture and testing of these vaccines under GMP/GLP conditions (FDA guidelines), conducting clinical trials for vaccine safety and effectiveness, and obtaining regulatory approvals to move the product forward. GeoVax's vaccines are unique in expressing virus like particles that display the trimeric membrane bound form of the HIV-1 envelope glycoprotein. All preventative Phase 1 human clinical trials conducted to date tested various combinations and doses of our DNA and MVA vaccines, their ability to raise anti-HIV humoral (antibody) and cellular (cytotoxic T cell) immune responses, as well as, the vaccines' safety. Successful results from Phase 1 testing supported the initiation of Phase 2 testing and the extension of clinical testing to include a granulocyte macrophage-colony stimulating factor (GM-CSF) adjuvanted version of the vaccine.  GeoVax is also enrolling patients in a Phase 1 therapeutic trial for individuals already infected with HIV. For more information, please visit www.geovax.com.

About the HVTN

The HIV Vaccine Trials Network (HVTN) is the largest worldwide clinical trials network dedicated to the development and testing of HIV/AIDS vaccines. The HVTN is an international collaboration that conducts all phases of clinical trials, from evaluating experimental vaccines for safety and the ability to stimulate immune responses, to testing vaccine efficacy. Support for the HVTN comes from the National Institute of Allergy and Infectious Diseases (NIAID), part of the U.S. National Institutes of Health (NIH). The Network's HIV Vaccine Trial Units are located at leading research institutions in 27 cities on four continents. The Network's headquarters are at the Fred Hutchinson Cancer Research Center in Seattle, Washington.

Forward-Looking Statements

Certain statements in this document are "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act These statements are based on management's current expectations and are subject to uncertainty and changes in circumstances. Actual results may differ materially from those included in these statements due to a variety of factors, including whether: GeoVax can develop and manufacture its 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, GeoVax will be able to enter into favorable manufacturing and distribution agreements, 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. More information about these factors is contained in GeoVax's filings with the Securities and Exchange Commission including those set forth at "Risk Factors" in GeoVax's Form 10-K.

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The Investor Relations Group
Erika Moran, Investor Relations
Janet Vasquez, Public Relations
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SOURCE GeoVax Labs, Inc.