HIV Vaccine

HIV Vaccine

Currently, there are no HIV vaccines are approved for use outside of clinical trials. Vaccine development involves using a disease-causing agent (e.g., virus, bacterium) to stimulate the immune system to recognize the agent and launch a protective response. Once the immune system recognizes the virus or bacterium and develops antibodies, vaccination (injecting a person with a vaccine) establishes immunity to the disease.

A vaccine that protects people from infection (i.e., people who are HIV-negative) is called a preventative vaccine and a vaccine that prevents disease in infected people (i.e., people who are HIV-positive) is called a therapeutic vaccine. In some cases, people who have been repeatedly exposed to HIV remain HIV-negative or never develop AIDS. These people may have developed natural immunity to the human immunodeficiency virus (i.e., their immune system recognized HIV and their immune response successfully eliminated the virus). The fact that a person can be exposed to HIV and never develop HIV/AIDS indicates that the immune system is capable of successfully responding to HIV infection.

Some studies have shown that patients who are infected with HIV-2 may be less likely to become infected with HIV-1. In these cases, HIV-2, which is weaker than HIV-1, may be acting like a vaccine and instructing the immune system to recognize and mount an immune response to the more potent HIV-1.