Another Sars outbreak on the mainland is unlikely this winter, according to Chinese and Japanese medical experts. There is also little chance that a Sars vaccine will be ready by the winter, the Guangzhou-based Information Times reports. The medical experts and health officials were attending a Sino-Japanese Sars prevention forum that began on Sunday in Guangzhou, where control measures and treatment successes were also discussed. The report quoted Zhong Nanshan, director of the Institute of Respiratory Disease, as saying that a Sars vaccine had not been found. He said antibodies that seem to stop Sars in animals should be investigated further, and an anti-Sars nose drop was being developed. 'It's reasonable to believe that a vaccine may not be developed for two or three years,' Professor Zhong said. New categories had been created to treat and more accurately diagnose Sars, the report said. They include non-Sars cases, non-suspected Sars cases, suspected ones, those clinically diagnosed and confirmed. The report said another Sars outbreak would not occur if appropriate control and prevention measures were taken. World Health Organisation spokesman Bob Dietze agreed. 'Even if Sars returns, it doesn't mean we'll have the same scenario that we had earlier this year. This time we know better what we are dealing with. What worked last time will work this time, too. 'As for the Chinese government, we ask them to keep up enhanced surveillance, to keep a close eye on certain areas - like southern China - and on certain groups of people - like health-care workers and people in the wild animal trade.'