Tuesday, 28 October 2014

The curious case of the sex workers who can't get HIV

SUNDAY 26th OCTOBER – SESSION 1 – PRINCIPLES OF HIV TRANSMISSION AND INFECTION: (Led by Amapola Manrique - Global Vaccine Enterprise)

WYCLIFFE MUGA writes: Some years ago, a small group of commercial sex workers – actively pursuing this line of work in a Kenyan slum (Majengo in Nairobi) were identified as having an innate immunity to the HIV virus. They had apparently been repeatedly exposed to HIV+ve customers, and yet had not once tested positive for HIV themselves. My question was, how is it that these women cannot get HIV infection, no matter how many HIV+ve men they have sex with? And why has this not led to any breakthroughs in the fight against AIDS?

The answer is that most ‘live’ HIV research is conducted using monkeys. Monkeys have their own variety of what in humans is HIV. It is called SIV – Simian Immunodeficiency Virus (as opposed to HIV being ‘Human Immunodeficiency Virus) – and apparently can exist in the bodies of monkeys without doing any real harm. So research in monkeys can give all kinds of insights and data about how these viruses behave. But there are obvious ethical barriers to what can be done to study a human being who simply cannot get infected with HIV despite repeated (and indeed, overwhelming) exposure to the virus.

This is a world-class conference on HIV. Many speakers are leaders in their fields. And yet what one hears all the time is, “Nobody knows”. For example, nobody knows why those women in the Majengo slums cannot get infected by HIV despite being engaged in (mostly unprotected) sex work. Nobody knows why - in 70% to 80% of infections - it is a single virus only, that will move across the vaginal (or rectal) mucosa and pass on HIV infection between sex partners. It all suggests a selective process: but nobody knows how or why.

But that is the way of science: again, contrary to popular assumption, it is not about one heroic figure emerging who will somehow come up with the shattering insight which finds a key to an AIDS cure or an AIDS vaccine which effectively stops all new transmission.

Victory against AIDS will involve many small incremental steps, and the efforts of thousands of dedicated scientists around the world.

And this is why conferences as this one are important – they allow for networking opportunities between scientists, policy makers, the media, activists/advocates and many others who are collectively involved in the global effort to put an end to one of the most deadly scourges of our time, and possibly the greatest public health challenge of recent decades.

At the end of this first day in Cape Town, it is clear that I am not here to find out the answers to my questions, as provided by the top experts: I am here to learn what kind of questions the experts are asking each other.

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