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China develops first live vaccine against bird flu
By Zhao Huanxin (China Daily)
Updated: 2005-12-26 05:27
Chinese scientists have produced the world's first live vaccine against bird
flu and Newcastle disease - two killer infections for poultry, the Ministry of
Agriculture has announced.
The recombinant bivalent vaccine, developed by the Harbin Veterinary Research
Institute, will be a great boost to prevention and control of the two epidemics
in China as well as in the world, Chief Veterinary Officer Jia Youling told a
press conference in Beijing on Saturday.
In addition to injection, the vaccine can be administered orally, nasally or
by spraying, said Jia, also chief of the ministry's Veterinary Bureau.
The mass-application techniques can not only significantly reduce labour
costs, but also increase immunity among fowls, Jia said.
The shot will also be very inexpensive, as its production cost is only
one-fifth of the inactivated vaccines available on the market, he said.
While most people are familiar with bird flu, Newcastle infections are
endemic to many countries. The latter is also a highly-contagious viral disease
affecting both domestic poultry and wild birds, experts said, adding that
chickens are the most susceptible.
In September, Newcastle outbreaks killed at least 56,700 chicken on the
Chinese mainland, according to the latest veterinary bulletin published by the
ministry in October.
Chinese scientists at the Harbin institute in Northeast China's Heilongjiang
Province spent four years to develop the powerful antidote to both Newcastle and
bird flu, according to Jia.
Employing a technique called reverse genetics, the vaccine uses an attenuated
Newcastle vaccine strain LaSota as a vector, according to Bu Zhigao, a chief
scientist of the project.
Bu said experiments showed the vaccine can also protect mammals, such as
mice, from bird flu.
Research and production techniques will provide reference for developing new
vaccines for human infections of bird flu, Jia said.
The ministry expedited the examination and approval process of the new
vaccine after the efficacy and security of the vaccine were satisfactorily
proved.
Mass-production of the new vaccine was approved on December 23, and by the
end of this month, 1 billion shots would have been produced, he said.
The vaccine will be used from the beginning of next year alongside other
vaccines, he said.
Intensive vaccination efforts have paid dividends in China's fight against
the fatal H5N1 strain of the bird flu virus.
By mid-December, 6.85 billion domestic birds had been vaccinated, including
more than 5 billion since October, Jia said earlier.
As a result, the country has reported only one case of bird flu outbreak this
month.
China reported six human cases of bird flu this year, involving two
fatalities, and 31 outbreaks among poultry.
By last Thursday, 30 out of 31 outbreak sites had been lifted out of epidemic
isolation, according to ministry sources.
Figures on the latest Newcastle disease toll were not immediately available.
In a related development, the State Forestry Administration said on Saturday
that it would examine the performance of the monitoring stations for wild-animal
epidemic diseases across the country.
The checks, lasting till February 20, will ensure that the 150 national
stations and 402 provincial stations have contingency plans and adequate
information reporting mechanism, according to deputy director Zhao Xuemin.
(China Daily 12/26/2005 page1)
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