CHINA: Does Bird Flu Vaccination Work?

BEIJING - Since the end of 2005, China has ordered the compulsory immunisation of poultry with government-funded vaccines. But for this avian flu prevention to be successful, all concerned parties must work closely together. Unfortunately, the weakest link in China's system for preventing animal epidemics still lies at the grassroots level. 

   In November 2005, more than 2,000 chickens in Gao Wenbin's poultry farm in Hehua Villiage of Chuxioang city, Yunnan province was wiped out by the deadly H5N1 bird flu virus. The incident prompted a special visit and inspection from Vice Premier Hui Liangyu. 

   Gao had no idea how the chickens caught the virus. He had bought over 10,000 local chicks from neighbouring Guangxi Autonomous Region and injected them with bird flu vaccines manufactured in Inner Mongolia. The vaccines, however, did not have the Ministry of Agriculture licence, so they were deemed as sham. 

   Now, all the chickens in Gao’s farm have been injected with genuine vaccines provided free by the town's veterinary clinic. 

   Are these vaccines able to resist avian flu virus? 

HIDDEN DANGER 

   In the one year following poultry deaths in Gao’s farm, there wasn’t any public report on bird flu pandemic in Yunnan. However, calmness on the surface does not mean risks from avian flu have been eliminated. 

   
   On Oct. 30, 2006, a research team led by Guan Yi, director of the State Key Laboratory of Emerging Infectious Diseases at the University of Hong Kong, and Rob Webster of St Jude Children's Research Hospital in Memphis, United States, published a study titled 'Emergence and predominance of an H5N1 influenza variant in China' in the U.S.-based proceedings of the 'National Academy of Sciences Journal'. 

   
   Between July 2005 and June 2006, the team collected over 50,000 samples from poultry markets in six southern Chinese provinces including Yunnan, and found the H5N1 virus in some 1,300 samples. The rate for H5N1-positive chickens, ducks and geese is 0.5 percent, 3.3 percent and 3.5 percent respectively.       

   
   The study claims that in March 2005, the team first detected the prototype of a new Fujian-like strain of the H5N1 virus. This type of virus had already been transmitted to Hong Kong, Laos, Malaysia and Thailand. 

   
   After analysing some samples of chicken blood serum, the team observed that the bird flu vaccine China now uses was not effective for the Fujian-like breed. It also inferred that large-scale vaccination might, in fact, facilitate the gradual dominance of the Fujian-like virus. 

   
   The direct challenge that this study posed to China's compulsory immunisation policy led the Ministry of Agriculture to fiercely criticise the article. 

   
   On Nov. 7, 2006, Chinese media all carried an interview by state-run Xinhua news agency with scholars, who were rejecting reports about the emergence of a new bird flu strain. One of the experts present was Chen Hualan, director of China’s National Avian Influenza Reference Laboratory, which is responsible for the research and development of all bird flu vaccines in China.   

    Three days later, Jia Youling, China’s chief veterinary officer with the Ministry of Agriculture' Bureau of Animal Health, appeared together with Chen at a press conference of the State Council Information Office. “There is no such thing as a new ‘Fujian-like’ virus variant at all,” countered Chen. 

    Jia accused Guan Yi and his colleagues of unlawfully obtaining samples and conducting research using unscientific methodology. They questioned the reliability of the team's data and rejected its conclusions.    

    The World Organisation for Animal Health (OIE) and the United Nations Food and Agriculture Organisation (FAO), meanwhile, issued a joint statement saying the research team's conclusions would not be too surprising if they were verified. Avian flu viruses, after all, are known to mutate fairly quickly. 

    In an interview with 'Southern Weekend', Guan Yi said: “We have kept all the original samples for our data. They could come and check on it. We didn’t collect samples because there was an epidemic outbreak. Instead, we collected random samples in the markets, about 100 to 200 per day, without interval, so as to follow the movement of bird flu viruses in China. This year, we had a much higher rate of viruses detected from poultry samples than last year, with serious scenarios in chickens after immunisation. Virus rate detected from ducks and geese also doubled or tripled. Why is this? Many bird flu patients in China were infected with the Fujian-like strain. Although at the moment chickens are not dying, what if people start to die?” 

    Jia Youling, in turn, questioned the team's “professional ethics”, saying that a million people's lives could have been put at risk had the team failed to report a possible outbreak.    

    “The state key laboratory I work with is affiliated to the Ministry of Science and Technology. Before I published my study, I had reported to both the Ministry of Science and Ministry of Health. The Ministry of Agriculture should also have had access to that,”  said Guan Yi. 

    The study also claimed that its monitoring network in southern China had the most comprehensive data on the evolution of H5N1 virus -- while in contrast, China lacked a state-level systematic surveillance on bird flu. 

    In a press conference, Jia Youling revealed that from January to October 2006, the national veterinary services tested 305,000 pathogenic samples from poultry and wild birds. Among poultry samples, 25 turned out to be positive for bird flu, all of which came from Yunnan, Guangdong and Xinjiang provinces. A total of 16 wild birds from Liaoning, Qinghai and Tibet also tested positive. 

    An expert who prefers to remain anonymous noted: “Although there are fewer public reports on the pandemic, it doesn’t mean the government pays less attention to avian flu prevention.” 

    Up to the end of November 2006, 21 people had tested positive for bird flu in China. Of this figure, 14 had died. Worldwide, there had been altogether 258 human bird flu cases, with 154 deaths. 

    Nonetheless, Ms Wang, a villager living near Gao Wenbin’s poultry farm, still does not know that bird flu has already caused human deaths. 

98% -- AN UNATTAINABLE TARGET? 

   Under the government’s seemingly lax strategy on bird flu, the role of vaccination has been placed at an unprecedented high level. 

   According to a 'Yunnan Daily' report, Yunnan Province deputy governor Kong Chuizhu pledged that poultry vaccination, of utmost important in the  prevention of bird flu, would be given top priority. His target was to have all poultry in the province vaccinated before mid-December 2005. 

    Li Jinxiang, deputy chief of the Bureau of Animal Health, also pledged at a press conference an average vaccination rate of over 98 percent for poultry in the country by June 2006. 

    In reality, however, even 98 percent is a difficult target, let alone 100 percent. 

    Song Xuelin, head of Yunnan Provincial Veterinary Epidemic Prevention Station, said only large-scale poultry farms could achieve the 100-percent vaccination target. Small, household farmers could hardly achieve it. Thus, the bird flu vaccination rate in the province would stand at over 80 percent higher in more developed areas and lower in remote regions. 

    According to him, some villagers were not willing to inject vaccines to their birds, for fear of frightening them, or killing the weaker ones. Even if small household farmers were all willing to give vaccine jabs, there are few people or resources to do the job. “Once you have the bullets, you still need to shoot,” he added.   

    Nonetheless, with the compulsory vaccination policy in China, bird flu vaccines have become a multi-million yuan industry. But what of its effects? 

    Chen Hualan, director of China’s National Avian Influenza Reference Laboratory, said that existing vaccines can protect waterfowl from the virus in southern China quite well, up to almost 100 percent even. She based her observation from laboratory experiments she has done in her laboratory. 

    However, vaccines injected in every place are not all effective it seems. In Chuxiong, Yunnan Province, the success rate for antibodies against bird flu at the end of 2005 was 93 percent. 

    Prevention results in autumn 2006 were even less ideal. For instance, the Veterinary Epidemic Prevention Station of Chuxiong Autonomous Prefecture ordered from Kunming, the provincial capital, a vaccine for both bird flu and Newcastle disease, a type of disease that causes mild conjunctivitis and flu-like symptoms in birds. The antidote had been successfully developed by China’s National Avian Influenza Reference Laboratory before the end of 2005. 

    However, surveillance results gave Li Chaocang, deputy chief for Chuxiong Prevention Station, a fright. The results showed only a 14 percent success rate for bird flu antibodies, with some farms having a zero pass rate. 

    Out of frustration, the Chuxiong Station had to use a vaccine solely meant for avian flu all over again, with a final antibody pass rate of 72 percent. Li quoted experts from Kunming as saying that there was no problem with the joint vaccine itself. Something might have gone wrong when farmers carried out the vaccination, he added.  

    Prof. Bi Yingzuo from South China Agriculture University said he could not comment since he did not know much about the exact circumstances around the Chuxiong incident. However, he added, immunisation is not a one-jab thing. The processing of the vaccines, animal susceptibility and careless immunisation practices could all affect the outcome of the exercise. Clearly, the lack of technical support in the grassroots level is a major factor.  

    In China, a village veterinarian plays a key role in the prevention of a bird flu pandemic. “Most of the village vets do their job out of kindness and for public welfare,” said Yang Ke, a technician working for a vet station in Ziwu Town. "In places where vaccination is well conducted, there are fewer animal diseases, which means income for the vet would decline. Therefore, some vets are not very responsible as expected. They might just use a syringe and pretend to inject.” 

    Lack of technical support and poor pay are juts the tip of the iceberg. According to Song Xuelin, vets are poorly paid and not skillful enough despite increased government support in the last few years. 

    Yang Peichang, head of the Chuxiong Vet Station, is extremely concerned about the vets’ professional qualifications. “The staff at our station is ageing. While the manning quota is full, new college graduates could not get in. What’s worse, people unqualified for the job have been squeezed into our station as a result of township institutional reform.” 

THE THAI STRATEGY 

  Among the Mekong countries, Vietnam is also doing avian flu vaccinations on a large scale. According to Dr Jeffrey Gilbert, avian flu senior technical coordinator for the U.N. Food and Agriculture Organisation (FAO) in Vietnam, with FAO support a vaccination drive was launched in 63 provinces in Vietnam during the autumn of 2005. However, in the following year, 33 provinces remained high-risk areas. It is estimated that 99 percent of the vaccines were from the well-reputed Harbin Veterinary Research Institute in northern China. 

   Apart from close cooperation among communities, Gilbert said continued surveillance of all poultry, with or without anti-bird flu jabs, is of vital importance. People need to understand how the virus spread in vaccinated or unvaccinated poultry and whether mutation has taken place. It is also important to ensure vaccinated birds develop resistance against the virus.   

    In sharp contrast, Thailand, another country in the Mekong region, has completely banned bird flu vaccines. 

    Pornthep Ratanakorn, associate professor with Mahidol University, believes that whether a country carries out vaccination or not depends on various elements, be it political, economic or technological. One general concern is how vaccination would affect the export of poultry products. Hence, Thailand has put more emphasis on measures other than vaccination to prevent bird flu. 

    Doi has a gamecock farm in Chiang Saen village, Chiang Rai in northern Thailand. An average gamecock needs dozens of square metres of wide, open space to roam in. These gamecocks are separated from each other by barbed fence. Doi said a clean environment is vital for gamecocks to develop better resistance to diseases. 

    Doi has been in the trade for over 30 years and is quite a figure in cockfighting circles in northern Thailand. He owns a gamecock named Ath Het, which is now worth 100,000 baht (2,500 U.S. dollars). He used to take his gamecocks across the border to Simao, Jinghong and Kunming in southwest China’s Yunnan. However, since the outbreak of bird flu three years ago, China has stopped allowing live poultry to cross its borders. 

    Although Chiang Rai hasn’t witnessed any bird flu epidemic, the rule in Thailand is for every gamecock to have a 'passport' if it fights in another province, an important managerial method on migrating poultry. 

     Duck King Co. Ltd. in central Thailand practices enclosed farming, which keeps the ducks away from direct contact with people and other fowls. An advisor with the company said samples are collected every eight weeks for local vets to check. 

     According to a local veterinary officer, the number of poultry farms had dropped from 1,200 to 430 since bird flu broke out in Thailand in 2004. Those without biosafety measures were all closed down. What's more, government orders that poultry farms should be at least five kilometres away from each other. 

    According to Dr Supamit, senior expert for Thailand’s Health Ministry on disease control, the five-kilometre distance policy referred to as “compartment”, is a new measure in the country’s bird flu prevention. “As to its effect, it might not be clear until five to ten years later,” he added. 

    Towards the end of 2005, Kenan Institute Asia, a non-governmental organisation, has been engaged in school education on avian flu prevention in Thailand. James Hopkins, head of the programme, said relevant textbooks have been dispatched to 40,000 schools in the country. “This is the first time that a specific public health training textbook was sent out to every school,” he added. 

    After the Sep 19, 2006 coup d'etat in Thailand, there had been renewed discussions on whether the country should follow China’s immunisation policy. One group favors vaccinating gamecocks that traveled long distance and free-range poultry without bio-safety measures to reduce the risks of bird flu transmission. 
 

    Toward the end of 2005, Kenan Institute Asia, a non-governmental organisation, has been engaged in school education on avian flu prevention in Thailand. James Hopkins, head of the programme, said relevant textbooks have been dispatched to 40,000 schools in the country. “This is the first time that a specific public health training textbook was sent out to every school,” he added. 

    After the Sep. 19, 2006 coup d'etat in Thailand, there has been renewed discussions on whether the country should follow China’s immunisation policy. One group favors vaccinating gamecocks that traveled long distance and free-range poultry without biosafety measures to reduce the risks of bird flu transmission. 

    Hopkins is planning to conduct a forum on the prevention of cross-border bird flu among the Mekong countries. “Some countries don’t want to publicise the avian flu epidemic, preferring to deal with it internally. But bird flu is no longer a country’s internal affair. Every country will have to share information and work together,” he said.    

OTHER MEASURES NEEDED 

   Bird flu prevention has become a long-lasting struggle. Vaccination, said Song Xuelin, is not the only preventive measure. There are, after all, different kinds of bird flu and viruses are constantly mutating. One vaccine could only target one virus. What is critical is the animal's resistance to such diseases. Therefore, improving hygiene and managing enclosed poultry farming are both very important. 

    Both the OIE and FAO, meanwhile, regard vaccination as one of the measures for bird flu control. The two groups also stressed on disease monitoring and surveillance after vaccination, apart from improved hygienic practices in the farm and efficient management of poultry transport. 

    However, in Chuxiong, Yunnan Province, prevention measures are not satisfactory even in large-scale farms. At Gao Wenbin’s farm, dozens of chickens still roam out of the enclosed area and stroll in front of the dorms of the farm staff. The air reeked of chicken feces. Dozens of meters away is Lao Jin’s duck farm where over 2,000 ducks were raised in the open air, many of them playing in a pond nearby. 

    In a report on bird flu prevention, Chuxiong Animal Husbandry Bureau advocated a change in poultry farming to scale farming. But Li Haifen, head of the vet section in the bureau, said so far no concrete measures have been mapped out. 

    In contrast, the monitoring of avian flu in humans is much better. Since vaccines for human bird flu cases have yet to be developed, the health sector has no recourse but to rely more on the monitoring system.        

    Although there has not been any human bird flu case in Yunnan, officials should be wary of the risks. Yunnan Provincial Centre for Disease Control and Prevention (CDC) director Lu Lin revealed that a preliminary flu and human avian flu monitoring network, as well as vaccinations, have been set up in the province. Qujing City, Honghe Prefecture and Yunnan Province have all joined hands in this endeavor. Six hospitals will become observation posts, collecting samples all year round. 

    What’s more, a direct reporting network has been established in Yunnan for pneumonia cases of unknown causes and human bird flu cases within two hours of diagnosis, so that both the health minister and the national CDC are able to read case reports at the same time. Only the person who sends the report can make changes regarding the content, whereas CDCs at different levels could only read the report online.  

    However, in Chuxiong, Yunnan province, prevention measures are not satisfactory even in large-scale farms. At Gao Wenbin’s farm, dozens of chickens still roam out of the enclosed area and in front of the dorms of the farm staff. The air reeked of chicken feces. Dozens of meters away is Lao Jin’s duck farm, where over 2,000 ducks were raised in the open air, many of them playing in a pond nearby. 

    In a report on bird flu prevention, the Chuxiong Animal Husbandry Bureau advocated a change in poultry farming to scale farming, or commercial farming, which is assumed to be able to take on the required biosafety measures. But Li Haifen, head of the vet section in the bureau, said that no concrete measures have been mapped out so far. 

    In contrast, the monitoring of avian flu in humans is much better. Since vaccines for human bird flu cases have yet to be developed, the health sector has no recourse but to rely more on the monitoring system. 

    Although there has not been any human bird flu case in Yunnan, officials should be wary of the risks. Yunnan Provincial Centre for Disease Control and Prevention (CDC) director Lu Lin revealed that a preliminary flu and human avian flu monitoring network, as well as vaccinations, have been set up in the province. Qujing city, Honghe prefecture and Yunnan province have all joined hands in this endeavor. Six hospitals will become observation posts, collecting samples all year round. 

    What’s more, a direct reporting network has been established in Yunnan for pneumonia cases of unknown causes and human bird flu cases within two hours of diagnosis, so that both the health minister and the national CDC are able to read case reports at the same time. Only the person who sends the report can make changes regarding the content, whereas CDCs at different levels can only read the report online. 

   In Yunnan, the provincial health and agriculture departments have initiated a new response mechanism in the wake of a bird flu epidemic, under which the two departments would intervene, report and deal with the pandemic simultaneously. 

   Lu noted that transparency is a must. Even if only one or two free-range poultry are suspected of carrying the virus, the health department should be notified immediately. “If the health department was notified only after someone got infected, it would be too late.” 

(Li Hujun of Nanfengchuang magazine wrote this story under the Avian Flu Series of the Imaging Our Mekong programe (2006-07), coordinated by IPS Asia-Pacific and Probe Media Foundation Inc. The story was published Southern Weekend on Jan. 11, 2007.)