Yin Weidong, a leading expert for China's huamn bird flu vaccine project, said the research group has made preparations to produce human-use bird flu vaccine in massive quantities.

Yin's research shows that the biological properties of the virus strain remain the same as the original even after developing a tenth generation which displays a steady inheriting process, indicating that the virus strain can be used in large quantity vaccine production.

The Beijing-based Sinovac Biotech Co Ltd. led by Yin started cooperation with the Chinese Center for Disease Control and Prevention in 2004 and successfully developed a human bird flu vaccine in November 2005 which is currently under clinical tests that will last about 12 months.

Yin said the group adopted a researching concept earlier proposed by the European Union that is to research the immunity, security and effectiveness of the dangerous "prototype" H5N1, H9N2and H7N2.

If the virus mutates, new vaccines can be easily developed on the basis of those prototypes.

"We are capable of producing vaccines against other types of influenza if the virus develops into other forms," said Yin, who is also the managing director of Sinovac. "We can modify the virus strain within 48 days and update the human bird flu vaccine in four months after the virus mutates."

The flu virus easily mutates, which can disable any powerful vaccine, said Wang Xiaofang, director of the rural and social development department under the Ministry of Science and Technology.

Therefore, Wang said, the capability to research, develop and produce vaccines is much more important than vaccines themselves.

"Such storage of virus strains resemble duplicating machines in that we can quickly copy and update any prevailing flu virus on the basis of those established arenas," said Wang.

High-risk groups, such as poultry farm workers and medical staffers in the bird flu outbreak areas will be vaccinated as long as the vaccine passes a safety test, Yin said.

(Xinhua News Agency December 29, 2005)