Surviving HIV: HIV-2 infection in Guinea-Bissau

'Living with HIV', for those fortunate enough to have access to drugs, has come to mean a lifelong dependence on antiviral medication. But for the people of Cáio, a village in Guinea-Bissau, a diagnosis of HIV is not necessarily either a death sentence or a commitment to a life of medical treatment. That's because most of them do not have HIV-1, the strain that causes AIDS, but a similar virus called HIV-2 that is largely confined to West Africa.

'We're interested in this virus', says Professor Sarah Rowland-Jones who is based in Oxford's Weatherall Institute of Molecular Medicine, 'because most people with HIV-2 have a normal life.' Professor Rowland-Jones studies the immune response to HIV, work that could provide leads for others in Oxford, such as Professor Andrew McMichael and Dr Lucy Dorrell, who are developing new vaccine strategies against HIV. 'An effective HIV vaccine is desperately needed,' she says, 'particularly in the developing world where the burden of HIV disease is greatest.'

She first went to Cáio while working from 2004 to 2008 as director of the Medical Research Council's laboratories in The Gambia, across the border from Guinea Bissau. The MRC has had a field station in the village since 1989. 'When samples were first collected, over 20 years, researchers found that about 8 per cent of the adults were positive for HIV-2', she says. 'Yet many of them live into old age: most of the cohort are ladies in their seventies and eighties who are completely well and have had HIV-2 for two or three decades.'

The difference between the 20 per cent that progress to full-blown disease, and the majority who stay healthy, is that the latter are able to mount a much stronger immune response against the virus. As a result it does not cause the devastating damage to the immune system that is the hallmark of AIDS. Professor Rowland-Jones and her colleagues are investigating how it is that some people are able to generate this protective response and not others.

At the same time she has another project underway in Zimbabwe, working in collaboration with the University of Zimbabwe. Here colleagues have identified a group of children who acquired HIV-1 from their mothers at birth but were not diagnosed until much later. While most such children die early in life, these have been able partially to resist the infection and, though they are by no means well, are still alive in their teens.

'The ultimate aim of both projects is to try and understand protective immunity against HIV in a way that would help both design and also evaluate new vaccine candidates', she says. 'There's a feeling in the field that an effective HIV vaccine is possible, but we've still got some way to go.'