[Vaccines against HIV].

Vaccination has traditionally been the only way by which virus infections have been controlled and eliminated. An effective vaccine will be the best way to control the HIV/AIDS pandemic, especially in the developing world where antiretroviral drugs are not available for the majority of persons living with HIV infection. Much is known about the mechanisms that provide protection against virus infections. Advances in technology have provided possibilities for developing new vaccine strategies and vaccine delivery systems. A major challenge to the development of an HIV vaccine is the high degree of genetic variation among virus isolates. Recent research results indicate that it may be possible to design a single vaccine that is effective against multiple HIV subtypes. Despite great challenges there is reason to be optimistic. The development of a vaccine against HIV has been slow due to great scientific challenges and limited resources. Numerous promising candidate vaccines are currently in clinical trials. There will be an effective vaccine against HIV, but when remains an open question.