By Quentin Sommerville
BBC News, Shanghai
China says it plans to produce one billion doses of a new bird flu vaccine for animals.
Beijing aims to inoculate all the country's estimated 14bn poultry
The country's scientists have been working on the new vaccine for four years, according to state media.
It costs a fifth of current treatments, and there are hopes it could also help provide the basis for human protection against the deadly H5N1 strain of flu.
China is about halfway through the vaccination of its all domestic poultry - some 14bn chickens and ducks.
Mass production of the new vaccine has been given the go-ahead, and a billion shots will be produced by the end of the month.
The World Health Organisation says that China needs to change its farming practices if the spread of the H5N1 virus is to be stopped.
Scientists fear the strain could mutate from a disease that largely affects birds to one that can pass easily between people, leading to a human pandemic.
In many parts of China, people and birds live in close proximity.
The World Health Organisation has called for greater segregation between humans and poultry, if the spread of the virus is to be stopped.
China has seen 31 of bird flu this year. Six people became infected with the virus, two of whom died.