|Genetic Variability: Implications for the Development of HIV Vaccines (UNAIDS, 1996, 16 p.)|
Saladin Osmanov, William L. Heyward, Jossparza
Vaccine Development Unit,
Division of Research and Intervention Development,
Global Program on AIDS, World Health Organization,
Reference: Development and Applications of Vaccines and Gene
Therapy in AIDS
(International Workshop, Naples, June 15-16, 1995).
Editors: G. Giraldo, D.P. Bolognesi, M. Salvatore, E. Beth-Giraldo.
Vol. 48 Antibiotics and Chemotherapy
(Editor: H. Schonfeld).
Karger, Basel, 1996, pp 30-38.
More than 18 million human immunodeficiency virus (HIV) infections are estimated to have occurred worldwide since the beginning of the epidemic . If the present trend continues, by the year 2000 there will be a cumulative total of 30 to 40 million HIV infections in the world, with 90% of these infections occurring in developing countries. A safe, effective and affordable HIV preventive vaccine may be essential for the future control of this pandemic [2,3].
However, the development of such a vaccine will be a long and difficult process. Perhaps the two major scientific challenges for HIV vaccine development are the lack of information on immune responses known to correlate with protection against HIV infection, and the extensive genetic variability which is characteristic of this virus [4-7]. These two problems are interrelated. On the one hand, the lack of information on immune correlates of protection limits our ability to rationally design candidate vaccines based on a judicious selection of relevant B- and/or T-cell epitopes present in variable and/or conserved regions of the different viral proteins. Nevertheless, we do not know what could be the biological and antigenic significance of the observed HIV genetic variability. However, such variability has been generally perceived as a major obstacle to the development of broadly effective vaccines.