25 years after HIV discovery: prospects for cure and vaccine.

The impressive advances in our scientific knowledge during the last century allow us to have a much better vision of our origin on earth and our situation in the universe than our ancestors. Life probably started on earth around three and a half billion of years ago, and a genetic memory emerged early, based on an extraordinarily stable molecule, the DNA double helix, bearing a genetic code identical for all living organisms, from bacteria to men. We are thus the heirs of myriads of molecular inventions, which have accumulated over millions -sometime billions -of years. Environmental pressure has of course both maintained these inventions and also modulated them over the generations, through the deaths of individuals and sexual reproduction. For the last 30,000 years, our biological constitution has not changed: a hypertrophic cortical brain, a larynx to speak and a hand to manipulate. But for the last 10,000 years, another memory has emerged, which make our species quite different from the others: this is the cultural memory which transmits knowledge and societal organisation from generation to generation, through the use of language, writing and more recently virtual means of communication. This revolution occurred in various sites on the earth almost simultaneously through sedentarisation of human populations by agriculture, leading to several civilisations. Each human being thus receives two pieces of luggage: genetic memory at birth and cultural memory during all his life, and he will become a real human only if he is benefiting from both. For the last three centuries, particularly in the 20 th century, our scientific knowledge has increased exponentially and has diffused all over the world. We have a tendency to consider ourselves as pure spirits, but the hard reality still reminds us of our biological nature: each of us is programmed to die and, during his life, is exposed to diseases. At the dawn of this new century, we are still facing two major health problems: