US increases efforts after failed Aids trials

The US government is increasing its efforts to produce an Aids vaccine after a clinical trial last year failed to produce positive results.

Two trials undertaken last year by Merck & Co on new drugs, which had been ten years in development, failed to protect people and might even had made the risk of infection increase, experts have said.

Warner Greene, professor of medicine at the University of California, told Reuters: "Despite hundreds and hundreds of millions of dollars, the reality is that in 2008 an effective HIV/Aids vaccine is beyond our grasp."

Almost 30 potential new vaccines for Aids are tested around the world but scientists have said that after the outcome of the Merck trial, it showed how little was understood about the virus despite two decades of research.

The US budget for Aids vaccine research now stands at $854 million, up from $327 million in 2000.

Figures from the World Health Organisation show Aids infects 12,000 people every day and has killed 25 million people worldwide.