At the end of 2004 there were more than 40 million people infected Worldwide with HIV, with an estimated 16,000 new infections every day (UNAIDS, 2004). The HIV epidemic threatens whole societies particularly in Africa and Asia and rates of infections in the Western Countries have also increased over the last few years. However, despite more than 15 years of research, an effective vaccine against HIV and acquired immunodeficiency syndrome (AIDS) has still not been developed.