BEIJING — China's Agriculture Ministry said Tuesday that it would inject all of the nation's 5.2 billion chickens and other poultry with a vaccine against bird flu.
The campaign, disclosed by the official Xinhua News Agency, would be the largest single vaccination effort ever for any species, according to the U.N. Food and Agriculture Organization in Rome. It promises to be logistically complicated, not least because it entails chasing and catching billions of free-range birds.
The Agriculture Ministry did not provide a timetable.
At any one time, China has about 4 billion chickens and 1.2 billion ducks and geese, but even those numbers understate the size of the vaccination task. The country consumes about 14 billion domestically grown chickens, ducks and geese every year.
Dr. Qi Xiaoqiu, the director general of the department for disease prevention and control at China's Health Ministry, said at a news conference on Tuesday that three-fifths of the poultry in China were kept by families, who let the birds and other domesticated animals wander around the neighborhood and the yard and often through the house. Constant close contact between animals and people is worrisome because birds and pigs can carry the H5N1 bird flu virus and may transmit it to people.
"People raise pigs and people keep birds just like Americans keep dogs," Qi said. "Those pigs and birds are part of the family. It is a kind of self-sufficient, outmoded production method."
Qi also said it was "highly probable" that a boy and a girl who suffered high fevers last month — the girl died — were the country's first human cases of bird flu. Prime Minister Wen Jiabao warned last week that China faced a "very serious situation."
Qi and Roy Wadia, a World Health Organization spokesman here, said there had been no sign yet of human-to-human transmission of bird flu, a critical capability the virus needs to develop if it is ever to cause a human pandemic.
Kristen Scuderi, the U.S. Agriculture Department's deputy press secretary, said the United States had 40 million doses of bird vaccine in stock and another 30 million doses in production, which would be used to create a barrier zone around an area with a severe outbreak.
"The initial response is culling, but if the outbreak was really egregious we might go into the stockpile," Scuderi said. Some outbreaks have resulted in the deaths of millions of birds.