In non-human, pre-clinical studies, an AIDS vaccine produced by an Atlanta-based research organization proved to be 96 percent effective. The GeoVax vaccine, created on the Emory University campus, is currently undergoing Phase I human trials and could be available by 2011. It looks to solve one of the most significant medical challenges in combating AIDS.
The pace of mutation is one of the most difficult aspects of preventing and curing any virus. You can find a way to eliminate a virus, but unless it incorporates a slew of attack angles all at once, it’ll quickly fail. The virus will be able to evade the vaccine-induced immune system response. Because HIV has a high mutation rate, killing or deactivating it necessitates a series of coordinated attacks that can prevent or nullify its ability to mutate.
The GeoVax vaccination uses a two-step strategy to activate and then increase the two key immune responses in the human body to prevent the virus from escaping. Antiviral cells known as antigens bind to virus cells and deactivate them in the antibody response, white blood cells known as T-cells kill virus-infected cells in the cellular response. Overall, the infection is prevented from propagating. The vaccine can quickly and drastically assault HIV cells and eliminate them before they take hold of the body and weaken the immune system by concentrating on both system components (see How AIDS Work to learn what HIV and AIDS do to the body).
A DNA primer is given to a subject first. Three major genes in this primer represent the HIV genetic code. When these genes penetrate the body’s cells, the cells produce proteins to fight the alien DNA. This effectively trains the immune system to recognize HIV DNA and prepares it for an attack. As a result, the cells are already adept at producing the specific proteins that will alert T-cells to the presence of HIV cells in the body.
The live-virus injection is the next stage. When a small, weak sample of HIV enters the body, this happens. Infecting someone isn’t enough; only triggering an immunological response is sufficient. In this example, the individual is given MVA, a weak smallpox vaccination that has been genetically modified. This type of MVA contains not only smallpox virus components but also the three HIV genes found in the DNA primer. As a result, it not only promotes an immune response to smallpox but also to HIV. And the DNA-primed cells have already been programmed to combat this particular strain of HIV.
T-cells are prepared and ready to launch a major attack on three main components of the virus while the immune system sends out antibodies to bind to HIV cells and target them for destruction. The virus will not be able to escape because both of these anti-infection mechanisms are waging full-scale attacks simultaneously. Even if one of the genes mutates, the T-cells can still target and kill the other two, rendering the mutant gene ineffective. To begin with, the chances of a single gene mutating in a way that allows it to evade both a primed cellular response and a large antibody response are limited.