Approaches to the development of broadly protective HIV vaccines: challenges posed by the genetic, biological and antigenic variability of HIV-1: Report* from a meeting of the WHO-UNAIDS Vaccine Advisory Committee** Geneva, 21–23 February 2000

The Joint United Nations Programme on HIV/AIDS (UNAIDS) and the World Health Organization (WHO) estimate that since the start of the Human Immunode®ciency Virus/Acquired Immune De®ciency Syndrome (HIV/AIDS) epidemic close to 53 million people worldwide have become infected with HIV. An overwhelming majority of those infections have occurred in developing countries. Over the past years, the AIDS pandemic has claimed the lives of more than 18 million people, placing HIV/AIDS among three major fatal infectious diseases of mankind, together with malaria and tuberculosis.