Aids vaccine 'breakthrough' hopes dashed

The announcement last month that the controversial $105m (£64m) trial carried out in Thailand had unexpectedly been successful took experts by surprise and sparked excitement around the world amid speculation that the steady spread of HIV/Aids could before long be checked.

However, it is now clear that this is a long way wide of the mark.

The full results, presented at the Aids vaccine conference in Paris and published immediately online by the New England Journal of Medicine reveal that:

• The vaccine did not protect those at high risk of HIV infection, such as sex workers and intravenous drug users.

• The protective effect was greatest in the first 12 months and then seemed to diminish.

• When those who did not get all six vaccine shots were taken out of the analysis, the positive result was statistically insignificant.

Some scientists and campaigners in Paris nevertheless hailed the results, if not as a triumph, then as a beacon of hope. Dr Nelson Michael of the US army – the US military had run the research programme with the Thai government – said scientists would now be working intensely to pick up clues to future Aids vaccine development from the results of the trial. "It is a signpost for vaccine development," he said. "This was a yes-we-can moment: the opportunity to become enthusiastic. The door has cracked open. We are all going to try to collectively crash through it."