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News Agency Reviews China's Development of Avian Flu Vaccine for Humans

Posted on: Wednesday, 16 November 2005, 09:00 CST

Excerpt from report by reporters Zou Shengwen and Zhang Xiaosong by official Chinese news agency Xinhua (New China News Agency); subheadings as published:

Beijing, 15 November: Because of the global eruption of avian flu since last fall, large numbers of domestic fowls have been killed and many people who were infected by the virus died. In China, the epidemic has already occurred in five provinces and so the situation of controlling the epidemic is quite severe.[passage omitted]

China announced on the afternoon of 14 November 2005 that it had completed pre-clinical studies on the "development of avian flu vaccine for human." The announcement showed that China has achieved a major breakthrough and caught up with the advanced international standards in this field. The news soon attracted a high degree of attention from people in the country, and even people around the world.

China has material, technical capabilities to control avian flu

From fowls to human, the virus has broken through mankind's immunological defence. The development of avian flu vaccine for human will provide China with the most effective and most powerful weapon for fighting the epidemic.

Specifically because of this, Liu Yanhua, head of the Scientific- Technological Brainstorming Unit under the National Commanding Headquarters of Avian Flu Control and vice minister of science and technology, spoke highly of the success China has achieved in the "development of avian flu vaccine for human." She said: The development followed the established international and domestic procedures for developing and producing vaccines. It has come up with a vaccine for clinical tests. More importantly, it has created the procedures for scientific development, a matured technological system, and a complete technical platform.

"The technical system created for handling emergency, the rapid development capability and the matured technological system have made for China the technical preparations needed to fight pandemic that the avian flu might trigger. Now we are prepared for handling the problem." Liu Yanhua said, "Should a pandemic erupt, the Chinese government will be able to count on its development achievements to control the disease and safeguard the people's health and stable social development."

Wang Xiaofang, director of the Ministry of Health's department of agricultural and social services [Chinese: nong she si], maintained that avian flu and human flu viruses are easy to mutate and so vaccines for human use can easily become outdated. "This being the case, the capacity for developing vaccines and keeping them is more important than the vaccines themselves. Having this capacity is like having a 'vaccine duplicator.' If a virus becomes prevalent, we can 'duplicate' the necessary vaccine by means of the rapid development and production platform that has been created."

Wang Xiaofang said: Chinese scientists and researchers are now able to update a vaccine on the basis of a mutated virus. "If we discover that a virus has mutated, we can finish transforming [gai zhao] the virus within 48 days and develop a new vaccine within four months."

It was reported that preparations have been completed for installing in Beijing a production line for producing avian flu vaccine for human use. The production line will immediately begin production with state authorities' approval after all the clinical tests of the vaccine have been completed, or under an emergency situation.

A responsible person of authorities concerned indicated that the achievements will send this signal to the public: Avian flu can be prevented and controlled, and it is not dreadful. "We have a way to combat avian flu as long as we make scientific-technological arrangements before hand."

Avian flu vaccine clinical tests for humans will soon begin

[passage omitted] On 14 November, the Ministry of Science and Technology checked and approved the project - "development of avian flu vaccine for human" - and declared that China had completed the pre-clinical studies of the avian flu vaccine for human. Yu Yongxin, academician of the Chinese Academy of Engineering and responsible person of the group of experts who checked and accepted the development project, summarized the successes achieved in the development as follow:

- It has created the seed tank for re-matched [chong pei] vaccine strains suitable for vaccine production; studied virus' growth capability, hereditary stability, and deactivation effects and technology; and determined the technology for purifying vaccine and the method for testing virus;

- Proving the developed vaccine for experimental purposes is safe to use through experimenting its toxicity, abnormal toxicity and sensitivity on animals;

- Proving the vaccine has good immunity by conducting experiments on large and small mice; and

- Carrying out the pilot-production of vaccine and producing the vaccine useful for clinical tests.

It was reported that, on 21 October, the vaccine development unit already submitted a request to the State Food and Drug Administration for putting the vaccine on clinical studies. The China Centre for Certifying Drugs and Biological Products has completed the tests on the toxic strains for producing vaccine and issued a report on certifying the vaccine. Clinical tests of the vaccine will begin after the State Food and Drug Administration approved the tests.

It will take time before vaccine can be put to real use

Everybody knows that vaccination can soon build an immunity barrier among the people, stop the virus from spreading, and eventually conquer the flu. Then, will the avian flu vaccine be approved for marketing and vaccinating the people in the near future? The answer is negative.

First of all, the certification of the vaccine's safety and efficacy requires long clinical tests. According to an official of the State Food and Drug Administration, the producer of a vaccine cannot request to market the vaccine until it has to go through a three-stage clinical research process. So far Chinese scientists have completed only the pre-clinical studies and have yet to be approved for conducting the first-stage clinical tests. Although the state has built the "green corridor" for drugs to be used for controlling the avian flu, it has not reduced the number of the steps to be taken, nor has it lowered the standards.

Then, because a virus that triggers pandemic flu often has its specificity, the composition of the toxic strain in the vaccine must be matched with the toxic strain that triggers the pandemic. Thus, human still cannot produce the needed vaccine prior to the eruption of a pandemic. According to Yin Weidong, although the Beijing Kexing Biological Products Corporation has completed its studies on production technology, it still needs about six month before it can announce the production of the first vial of vaccine for combating the pandemic.

Meanwhile, seen from the vaccine production capacities of the world and China, it would be hard to come up within a short time the vaccine that can meet market needs if a pandemic does occur. According to Dr McHugh [ma xiu; name transliterated] head scientist of Sanofi Pasteur, the world's largest vaccine producer, the world's current production capacity is only 900 million vials of vaccine for the pandemic, but the world's population has exceeded six billion. Moreover, the quantity of eggs used for producing the vaccine will also become a factor that hinders vaccine production.

Nevertheless, in light of the pre-clinical studies, experts engaged in the "development of avian flu vaccine for human" still are full of confidence in the vaccine's clinical tests.

An official of the Ministry of Health indicated that once the clinical tests prove the vaccine is safe to use and establish the effective dosage and immunological procedures, the vaccine will be packaged and shipped to be used among the high-risk people, especially civil workers who take part in epidemic control in affected areas, fowl breeders, and medical personnel.

Currently, many countries are tightening up their efforts to develop avian flu vaccines for human. While China has caught up with the world's advanced standards in terms of the research results, China is not a forerunner. According to reports, the vaccine developed in the United States has already passed its tests on human and the optimal dosage of the vaccine is being determined. The vaccine developed in France is undergoing clinical tests and the country has developed the capacity for producing millions of vials. Moreover, the vaccine developed in Japan has also yielded good results from animal tests.

To hasten the process of developing the vaccine in the country, Yin Weidong suggested that the Chinese government should continue to support the vaccine development projects that own independent intellectual property rights and perfect the production technology; reserve the vaccine stoste in advance to be used for emergency vaccination among high-risk people; and, through increasing the vaccination against seasonal flu, encourage business concerned to increase vaccine output.

Source: BBC Monitoring Asia Pacific

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