Luc Montagnier, head of the Department of Virology at the Pasteur Institute (Paris, France) and Robert Gallo, now the director of the Institute of Human Virology at the University of Maryland (Baltimore, U.S.A.) are considered to be the men who discovered the virus that causes AIDS. Despite early controversy surrounding the systems and tests employed by each research team and the methods they used to publicise their breakthroughs, in recent years the two researchers have shared both a common approach and the international limelight in the fight against AIDS, and have worked on and researched new methods to combat this virus.

HIV causes AIDS. It is a disease that is passed on to six under-twenty-five-year-olds world-wide per minute, and that almost 34 million people throughout the world - over 23 million of whom inhabit sub-Saharan Africa - have suffered from since it first appeared. In 1999, 2.6 million people died of this disease (according to data from UNAIDS, the United Nations Aids Plan). Spain is the European country with the relatively largest number of cases caused by HIV infection. Calculations set the number of infected people at 200,000 (of which 58.8% are intravenous drug users, 20.3% cases are the result of unprotected heterosexual relationships, 12.5% from unprotected homosexual relationships, and in only 0.5% of cases is the disease passed on from mother to child, according to data from the Ministry of Health's National Aids Plan).

Robert C. Gallo (born 1937 in Connecticut, U.S.A.) studied medicine at the American universities of Jefferson, Philadelphia and Yale. He is a doctor in Medicine, and was intern at the University of Chicago from 1963 to 1965, when he joined the National Cancer Institute of the National Institutes of Health at Bethesda (Maryland, U.S.A.), where he became researcher in 1968, first heading the Cellular Control Mechanisms Unit between 1969 and 1972, and then the Laboratory of Tumour Cell Biology. Since 1995 he has been professor of Medicine at the University of Maryland, where he chairs the Institute of Human Virology, and collaborates with the Cancer Centre. He has written over one thousand publications.

His research has led to the discovery of the T-Cell, and the discovery and description of the first human retrovirus. He contributed to designing the first analysis to determine the presence of the AIDS virus in the blood. With twenty-five years of dedication to science to his credit, Doctor Gallo continues carrying out important scientific research, which has earned him the recognition of the international community.

He is an honorary professor at several universities, including Rochester and Ohio in America, and the Catholic University of Leuven in Belgium. He has twice been candidate for the Nobel Prize, and has been awarded the General Motors award (1984), the Armand Hammer Award for Cancer Research (1985), the Lasker Award for Clinical Research (1986), and the Gairdner Foundation Award.