The China National Agricultural Development Group Corp, the country's leading avian flu vaccine producer, said on Tuesday that its two subsidiaries capable of producing vaccines to inoculate birds are going all out in producing them to meet growing demand.

Two plants -- Qian Yuan Hao Biological Co in Zhengzhou, Henan Province, and Merial Nanjing Animal Health Co in Nanjing, Jiangsu Province -- have manufactured 500 million doses so far.

There are seven other plants on the mainland approved by the Ministry of Agriculture to produce the vaccines, on a list published by the ministry after it announced on Sunday that 13 other firms had been producing and distributing fake vaccines.

On Monday, it said it had discovered counterfeit vaccines in the northeastern province of Liaoning, the site of the most recent reported outbreak of bird flu in China. They had been produced in Inner Mongolia Autonomous Region on May 13.?

China National Agricultural Development Group has a daily production capacity of 4 million doses, ranking first on the Chinese mainland.

Bird flu outbreaks have been confirmed among bird populations in east China's Anhui Province, central China's Hunan Province, Inner Mongolia in the north and Liaoning since October 19.

Three possible but unconfirmed cases of human infection in Hunan are currently being investigated.

(Xinhua News Agency November 9, 2005)