Every 9-1/2 minutes, someone in the United States becomes infected with HIV. And, while a growing number of people have access to antiretroviral therapy for HIV/AIDS, scientists agree that treatment alone will not curtail the growing HIV/AIDS pandemic. For every person who begins treatment for HIV infection, two to three others become newly infected. Accordingly, scientists are racing against time to create an HIV vaccine to control, and ultimately end, this global pandemic.
Vaccines historically have been the most effective means to prevent and even eradicate infectious diseases. Preventive vaccines (often referred to as “immunizations”) are administered to healthy people to trigger the body's immune system to recognize and defend against harmful viruses or bacteria before the person becomes infected. (Preventive vaccines are widely given to prevent diseases like the flu, chicken pox, measles, mumps, rubella, polio, and hepatitis A and B.) This approach allows the body to set up defenses against those dangers ahead of time so that people won't get sick if exposed later.
Most people who are infected with common viruses recover from the infection, as their immune systems "clear" the viruses from their bodies. Once the body has cleared a particular virus, you generally develop immunity to it. Therefore, it won’t make you sick the next time you are exposed to it. Scientists have known since the late 1700s that exposing people to dead or weakened viruses can create immunity, protecting people from deadly diseases later.
HIV, however, is different from other viruses because the human body cannot seem to completely eliminate HIV from the body, nor develop immunity to it. The antibodies that the immune system makes to fight HIV become ineffective because HIV actually targets and attacks some of the most important cells in the immune system. Accordingly, over time, HIV does serious damage to the body's ability to fight disease. In fact, to date, no person with an established HIV infection has managed to clear the virus naturally.