The World Health Organisation has given a cautious welcome to news that an experimental HIV vaccine has — for the first time — cut the risk of infection.Researchers in Thailand say the vaccine, a combination of two earlier experimental vaccines, was given to 16,000 people in Thailand. Scientists say the vaccine reduced by nearly a third the risk of contracting HIV, the virus that leads to AIDS. Saladin Omanov, Coordinator of the WHO-UNAIDSHIV Vaccine Initiative said: “This is a huge scientific breakthrough but we don’t yet have a vaccine that could be applied to general population. We’ll need further tests to improve the current vaccine.” The findings, says the WHO, have instilled new hope that an effective commercial vaccine can now be developed. Thanad Yomha is one of the volunteers who took part in the experiment. He said: “I didn’t expect anything. I did this for others and as for me, considering how old I am, what we all do now is for the next generation.” Of 33 million HIV sufferers, worldwide, sixty seven per cent of those infected come from sub-Saharan Africa. It is feared the new vaccine may not be as effective in the area where it is most needed. The AIDS virus has killed 25 million people since it was first identified in the 1980s. It affects immune cells called T cells. Cocktails of drugs can control the virus, but, as yet, there is no cure.