At a major Aids vaccine conference in Paris, researchers have looked closely at recent vaccine trials in Thailand. The trials received serious attention because they apparently showed a two-vaccine combination that provided about a 31% protection rate for humans against HIV. Shortly after that promising report, however, further studies said the results might not be as promising as first thought. At this latest conference, all data has been set out and it is clear that the combo really does provide a modest effect, researchers said. Better than garlic, African potatoes, beetroot and olive oil, anyway.