SCIENTISTS have welcomed news that a trial of a vaccine for malaria has halved the number of cases in young children.

Interim results of testing of a vaccine called RTS,S developed by GlaxoSmithKline, which has a factory in Barnard Castle, County Durham, showed it had halved the number of cases in children between five and 17 months.

Professor Brian Greenwood of the London School of Hygiene and Tropical Medicine, who has contributed to the project and co-authored the paper detailing the results, said at a conference in Seattle: The School is pleased to have been able to contribute in various ways to the success of this important trial of the malaria vaccine RTS,S.

The interim results of this trial confirm the efficacy of this vaccine in infants and older children and take it a further step along the road to becoming the first malaria vaccine to be licensed and used in public health programmes. We now have confirmation of its promise as a potentially valuable tool in malaria control.

International Development Secretary Andrew Mitchell said: Vaccine research is very important and these results offer real hope for the future. An effective, long-lasting and cost-effective vaccine would make a major contribution to malaria control.

We need to understand how and in what circumstances a vaccine would be effectively delivered as part of a malaria prevention strategy and made accessible to the worlds poorest people.

But we must not lose sight of the fact that over two thousand people die from malaria every day and they need help now.

Britains focus remains on driving down this terrible loss of life by preventing and treating malaria with the tools we have now and tackling resistance.

The vaccine itself is thought to be still at least three years away. More testing must be completed to see how well it works and how long protection lasts.

It targets a malaria parasite found in sub-Saharan Africa.

The results from phase III trials of the vaccine were announced at the Bill and Melinda Gates Foundation Malaria Forum in Seattle.

Among five to 17 month old children, the vaccine prevented clinical malaria in 56 per cent of trial participants over a period of one year. It prevented severe malaria in 47 per cent.

Philanthropist Bill Gates said it was a huge milestone in the fight against the disease.

He added: "First, this is proof that it is possible to create a vaccine that is effective against malaria.

"Second, if further results show that the effectiveness of RTS,S does not wane over time, it has the potential to protect millions of children and save thousands of lives."

GlaxoSmithKline chief executive Andrew Witty told the Guardian newspaper that he was thrilled for the scientists who were thought by many of their peers to be attempting the impossible when they started work on a vaccine 25 years ago.

He said: "When the team was first shown the data, quite a number of them broke down in tears. It was the emotion of what they had achieved - the first vaccine against a parasitic form of infection. They were overwhelmed."