Slaughtered ducks are displayed for sale outside a shop in Kunming, southwest China's Yunnan province September 13, 2006. Chinese and United States health experts have developed new vaccines against the deadly H5N1 bird flu virus, which is believed to be able to cause a human pandemic flu, China Daily reported.[File Photo/Reuters]

"China is a very important partner in the international fight against avian influenza," David Heymann, interim WHO director for communicable diseases, told a news conference in Beijing.

"A Chinese virus has been used in this network (the WHO collaborating network) to develop what is called the prototype vaccine for pandemic influenza," he said. "So China contributes significantly and internationally."

Heymann said he had participated during the week in a "routine mission" to China on bird flu that had involved the WHO, the UN's Food and Agriculture Organization and the World Organization for Animal Health.

At the request of the Chinese ministers for health and agriculture, foreign and Chinese experts discussed "how China could contribute even more both by providing viruses and also by providing technical and scientific expertise to the world," Heymann said.

"The discussions were very productive," he added.

The H5N1 strain of the bird flu virus, which can be lethal to humans, reappeared in 2003 in southeast Asia and in China.

The largest number of cases have been detected in this region, with 57 people dying in Indonesia, 42 in Vietnam and 14 in China.