A vaccine against HIV would make a dramatic contribution to the fight against HIV/AIDS. Vaccines harness the human body's natural defenses by provoking an immune response, preparing the body to fight off the actual disease. Historically, vaccines have been responsible for greatly reducing the incidence of numerous fatal childhood diseases, and for eradicating smallpox.
There is widespread agreement within the scientific community that developing an AIDS vaccine is feasible, though complex. Evidence from primate studies and the case histories of people who have been repeatedly exposed but have not contracted HIV suggests that it is possible to achieve immunity. There are a number of different designs for a potential AIDS vaccine, but most of them use specific parts of HIV (genes or proteins) to stimulate the body's immune defenses. As with other vaccines, the idea is that the immune system will learn to recognize these viral components and mount a vigorous defense if infected with the actual virus. However, there are factors that make HIV different from other communicable diseases for which vaccines have been created.
While the biggest barriers to an HIV vaccine are scientific, vaccines are like other prevention technologies that require sufficient political will and resources to move forward.