AIDS researchers focus on resistant patients in search for vaccine

French AIDS researchers said Monday they hoped a vaccine could be developed using knowledge about the small number of HIV patients who manage to resist the virus without treatment over a long time.

"There is a minority of patients, less than one percent, who have found in their immune system the capacity for a robust anti-viral response, which is exactly what you'd expect from a vaccine," Jean-Francois Delfraissy, head of France's national AIDS research agency, told AFP.

Delfraissy and others have been studying how some HIV carriers manage to control the virus.
Their findings, published in US publication "Proceedings of the
National Academy of Sciences", show how some immune cells, called CD8 cells, are able to prevent the spreading of an HIV infection in a small number of patients.

Those patients remain HIV-positive because they continue to produce antibodies against HIV, but the infection is otherwise untraceable, and no treatment is required.

The researchers said the pivotal role of CD8 cells could lead to the development of a vaccine for those patients, a large majority, whose immune system cannot spontaneously activate their powerful anti-HIV potential.

Mutating and with several lines of defence, HIV has been the most redoubtable foe that vaccine designers have ever faced.

But in February, a US research team said it had taken a tiny snapshot of a key location on the tip of the HIV virus's docking spike that is stable und unmutating -- in other words, a fixed target.

The team said a that the spike was recognised by a specific antibody, called b12, found in the blood of people who are able to hold the virus at bay for long periods.