Asia must remain vigilant over the threat of swine flu, stepping up cooperation to produce vaccines and bolstering meager anti-viral stockpiles, AP cited top regional health officials as saying today. The virus has so far largely spared Asia. Only South Korea and Hong Kong have confirmed cases. On Thursday, China and Hong Kong released dozens of people quarantined over suspected contact with one of the region's few swine flu carriers. But with the memories of outbreaks of bird flu and severe acute respiratory syndrome, or SARS, that claimed hundreds of lives in recent years still fresh in their minds, delegates said it was no time to let down their guard. Health ministers from the 10-member Association of Southeast Asian Nations along with China, South Korea and Japan met in Bangkok to discuss precautions such as producing and holding vaccines and anti-viral drugs, expanding the ASEAN emergency stockpile of 1 million courses of Tamiflu and Relenza, improving surveillance and holding drills to test responses to an outbreak. «We are trying to harmonize the strategies among our members so there are no loopholes in the region,» said Dhannanjaya Sunoto, an ASEAN official helping countries prepare for an outbreak. «This is very important for us.» Dhannanjaya said it was too early to discount the impact of the flu, saying the 1918-19 flu pandemic should serve as a cautionary tale. It also began in the spring and was initially mild, but a much more lethal strain of flu hit six months later and the virus eventually killed 50 million worldwide.