Beijing (AsiaNews/Agencies) - Chinese scientists have developed two new vaccines for poultry and mammals to prevent the spread of bird flu, agricultural authorities have announced. The new jab is thought to protect chickens for at least 10 months, four months longer than existing drugs.
The developers have said the vaccines represent a breakthrough in the fight against the deadly H5N1 strain of the virus. But sources connected to the research project said the vaccines were not necessarily more effective than one now being used, which was also developed by the Harbin Veterinary Research Institute.
"Essentially there are no differences," said a source close to the institute's Key Lab of Animal Influenza, which developed the new vaccines. According to the Ministry of Agriculture, the vaccines can protect chickens against bird flu for 10 months - four months longer than the existing vaccine. But the source said the 10 months' protection was achieved under laboratory conditions and "we would consider ourselves very lucky if that happens in the real world".
He said tests also showed that the vaccines, which will soon go into use nationwide, did not protect ducks and geese as well as chickens, only providing protection for two or three months.
The source said the real challenge was finding an effective drug to vaccinate highly mobile water fowl, which are believed to be a reservoir of bird flu but do not usually display symptoms, and stop the spread of the virus in rivers and lakes.
The Harbin Veterinary Research Institute launched the vaccines mainly due to "market pressure", the source said. The institute, based in the capital of Heilongjiang province , was forced to come up with new products to help it reclaim some of the market share it lost last year after a challenge by rivals, the source said.
The H5N1 strain of bird flu has killed at least 45 people in Asia in the last year, including 13 in Vietnam in the past month. Chinese Premier Wen Jiabao has urged "all possible measures" to prevent the emergence of the disease in China. Although there have been no outbreaks reported in China so far this year, some places were not prepared for a possible outbreak, Xinhua said last month.Most bird flu victims have caught the virus from infected poultry, but experts fear it could mutate into a form that could easily pass between humans, unleashing a global flu pandemic that could kill millions.