"Take the HIV fight to them."

Take the HIV/AIDS fight to them, Former President Nelson Mandela urged as we were leaving: ‘Nothing that we have achieved in our country was without a fight. But I am too old now. You scientists must pick it up’ he remarked to his fellow Nobel Laureate David Baltimore.

Likely one of the most pre-eminent biologists specialising in viruses today, Baltimore briefed an obviously fascinated Mandela on what we know about the Human Immuno-deficiency Virus (HIV). It was a breathtaking preview of the full Nelson Mandela Science Lecture he was to give an hour later at WITS.

No spring chicken himself, Baltimore at 69 stepped off the flight that some morning, after two 11 hour-long flights from California. Most of us would wilt at the thought of such a travel schedule. None of this diminished the sharp edge of his intellect obvious to everyone who attended his lecture.

Micro RNA - a future blockbuster?

As Dr David Baltimore rose to speak a smoke and thunder of voices rattled the doors at the back of the Great Hall at the University of the Witwatersrand in Johannesburg. Protestors outside had threatened to disrupt his presentation of the third annual Nelson Mandela Science Lecture.

Baltimore is the President Emeritus and Robert Andrews Millikan Professor of Biology of the California Institute of Technology. His work on the identification of reverse transcriptase – the mechanism by which retroviruses, like HIV, infect cells - earned him the 1975 Nobel Prize in Physiology or Medicine at the age of 37.

Baltimore is in South Africa at the invitation of the Africa Genome Education Institute to speak on his experiences in searching for solutions to HIV.

Africa, with 10% of the world's population, has 60% of its infections. In 1994 South Africa, at the dawn of transition to majority rule, already had 850,000 people infected with HIV. In 2007, largely as a result of government negligence and the promotion of "alternative" remedies such as garlic and beetroot, there are 5.5 million South Africans who are HIV positive.

The discussion of HIV and AIDS in South Africa is not without controversy.

HIV Positive, and Deadly

Dr David Baltimore speaking on the occasion of the third annual Nelson Mandela Science Lecture at Wits University in Johannesburg, South Africa

Pigs with blue ears, Italians with an African infection, birds dying by the millions, beehives collapsing worldwide, 40 million people living with chimpanzee’s infection—what do all these have in common. They all show that viruses are not stable parts of our ecology; they show that viruses mutate continually and can change their properties dramatically. They show that all species, but especially humans, are at risk of infections with viruses that explode out of nature with little warning. This is my topic today, how viruses move around continually, presenting the world with one of its greatest challenges.

You may be disappointed to hear that I am going to talk about viruses. After all, this is the Nelson Mandela Lecture and he is such an extraordinary personal hero, such a deep thinker, such a committed man. Shouldn’t a lecture in his name say something about the world condition or about personal heroism or about bringing peace to the world?

My job here is to convince you that viruses are a threat to peace in the world, a threat to economic development, a threat requiring selfless devotion to our communities. And in particular HIV is threat to all nations that do not mount an offensive to counter the virus. There is hope but only if we recognize the nature of our enemy. I think it is a topic worthy of being considered in the name of Nelson Mandela.

But to do this I need to make sure that we all understand what a virus is. So I will start there and then broaden out my concerns with a special focus on human immunodeficiency virus, HIV, the cause of AIDS.