The “Durban Declaration”, which is published as a Commentary on page 15, has been signed by scientists, doctors and senior representatives of all the world's leading medical and scientific research organizations and government authorities engaged in HIV/AIDS research or policy — UNAIDS, medical research institutes, leading universities and independent research foundations. But, crucially, the declaration is also supported by health ministers, AIDS experts and public-health officials from countries in Africa, Asia and elsewhere in the developing world (see page 3).

The declaration is a massive international response to recent debates in South Africa, and is made on behalf of people infected with HIV. Frustrated at a needless and tragic delay in treating sufferers, the authors see the declaration as a decisive rejection of arguments put forward by many of those on a panel set up by South African President Thabo Mbeki to “re-evaluate” the cause of AIDS. As described in the declaration, the evidence for HIV as the cause of AIDS is overwhelming. Drugs such as AZT can be used relatively cheaply and effectively to reduce mother-to-child transmission of this virus. (Readers interested in further details about HIV as the cause of AIDS can see http://www.niaid.nih.gov/factsheets/evidhiv.htm. Those wishing to assess the opponents' case might visit http://www.duesberg.com.)

Unlike some websites disputing the evidence that HIV is the cause of AIDS, to which anyone can apparently add their support regardless of their expertise, the Durban Declaration is signed only by scientists and representatives of organizations involved in research and treatment of AIDS. That is not the reason Nature endorses their position, however — indeed, Nature takes pleasure in publishing papers that convincingly overturn widely accepted hypotheses. It is, rather, on the compelling basis of the science that we urge that the declaration's message be acted upon by President Mbeki and his government.