HIV Vaccine Trials Network Opens Enrollment for Phase 1 Trial of GeoVax Labs' Second Generation HIV Vaccine

Total of 48 Subjects To Be Enrolled at Four Sites Across U.S.

ATLANTA, May 22, 2012 /PRNewswire/ -- GeoVax Labs, Inc. (OTCQB/OTCBB: GOVX), an Atlanta-based biopharmaceutical firm developing vaccines to prevent and fight Human Immunodeficiency Virus (HIV) infections, today announced that the NIH-funded HIV Vaccine Trials Network (HVTN) has opened enrollment for a Phase 1 trial for the company's second-generation HIV vaccine. The second-generation vaccine is identical to the first generation (currently in a Phase 2a clinical trial) except for the inclusion of granulocyte-macrophage colony-stimulating factor (GM-CSF) as an adjuvant (additive) to enhance vaccine responses. GM-CSF is a normal human protein that promotes the initiation of immune responses. GeoVax's second-generation vaccine co-expresses GM-CSF with HIV proteins in the DNA priming vaccinations. GM-CSF is not included in the MVA boost for the GeoVax DNA prime-MVA boost regimen.

The trial, designated HVTN 094, employs a dose-escalation to evaluate the safety and immunogenicity of the GM-CSF adjuvanted vaccine. In the non-human primate model, co-expression of GM-CSF in the DNA prime achieved a 90% per exposure reduction in infection, a significant improvement over the unadjuvanated vaccine. This difference in vaccine efficacy translated into 70% of vaccinated animals being protected against 12 repeated rectal challenges. Assuming a successful outcome, the company expects the adjuvanted version of the vaccine to be carried forward into Phase 2a/2b efficacy testing.

The HVTN 094 trial will enroll a total of 40 vaccinated and 8 control/placebo subjects to be studied at four sites nationwide: the University of Alabama at Birmingham; Brigham and Women's Hospital, Boston; the University of Rochester, and the San Francisco Department of Public Health. The first inoculation was given at Brigham and Women's Hospital, Boston. Funding for HVTN's conduct of the trial will come from the National Institute of Allergy and Infectious Diseases (NIAID), part of the U.S. National Institutes of Health (NIH).

Robert McNally, Ph.D, President and Chief Executive Officer of GeoVax, said, "We are extremely pleased the HVTN is conducting the trial with the adjuvanted vaccine. They have substantial experience with our unadjuvanted vaccine and possess appropriate expertise for this first human trial of our GM-CSF co-expressing vaccine that has shown such good promise in preclinical studies."

About GeoVax
GeoVax Labs, Inc. is a biotechnology company developing human vaccines for HIV (Human Immunodeficiency Virus – that leads to AIDS). GeoVax's HIV/AIDS vaccine technology is exclusively licensed from Emory University in Atlanta, GA, and is the subject of more than 20 issued or filed patent applications. GeoVax vaccines are designed for use in uninfected people to prevent acquisition of HIV-1 and limit the progression to AIDS should a person become infected. GeoVax vaccines are also being tested as a therapeutic treatment (for people already infected with the HIV-1 virus).

GeoVax's core vaccine technologies were developed by Dr. Harriet Robinson, Chief Scientific Officer, through a collaboration of colleagues at Emory University's Vaccine Center, the National Institute of Allergy and Infectious Diseases (NIAID), the Centers for Disease Control and Prevention (CDC) and GeoVax. The technology uses recombinant DNA to prime the immune response and recombinant modified vaccinia Ankara (MVA) to boost the primed response.  Both the DNA vaccine and the MVA vaccine express non-infectious virus-like-particles displaying the natural trimeric form of the HIV envelope protein.

GeoVax's vaccines have moved forward in human clinical trials conducted by the HIV Vaccine Trials Network (HVTN) based in Seattle, Washington. These trials have tested various combinations and doses of the 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 Phase 2 testing in an ongoing, fully enrolled, 299 participant trial in North and South America.  The vaccine is also undergoing Phase 1 /2 testing as a therapeutic in HIV-infected individuals.

About the HVTN
The HVTN is the largest worldwide clinical trials network dedicated to the development and testing of preventive 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.

About NIAID
NIAID conducts and supports research—at NIH, throughout the United States and worldwide—to study the causes of infections and immune-mediated diseases, and to develop better means of preventing, diagnosing, and treating these illnesses. News releases, fact sheets and other NIAID-related materials are available on the NIAID Web site at http://www.niaid.nih.gov/.

For more information, please visit www.geovax.com.

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: HVTN will commence, complete enrollment, and generate data regarding GeoVax vaccine clinical trials as and when expected, 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, less costly, 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.

Contact
The Investor Relations Group:
Erika Moran, Investor Relations
Janet Vasquez, Public Relations
(212) 825-3210

SOURCE GeoVax Labs, Inc.