Fears of a devastating new global influenza epidemic have scientists keeping a wary eye on a strain of avian flu that has killed more than 60 people in Southeast Asia since 2003. Scientists are racing to develop a human vaccine for the H5N1 bird flu virus before it becomes more contagious, and one may be produced in the United States. In the meantime, Vietnam, the country hardest hit by bird flu, is starting to target the virus at its source by vaccinating its entire poultry population.
The sound of healthy chickens is music to the ears of Vietnamese farmer Tran Sy Ngu, who relies on selling the eggs from his two thousand hens to earn about $200 a month.
Mr. Ngu has been lucky so far. While the outbreak of avian flu in Vietnam has forced the country to cull some 50 million chickens and ducks, Mr. Ngu's flock has remained healthy.
This is partly because he disinfects his enclosures at least twice a week. But he worries that even this precaution might not be enough to protect the birds. That is why Mr. Ngu is eagerly awaiting a new government poultry vaccination program that started this month.
Mr. Ngu says he thinks the government vaccination program is very good. He is hoping the program will come to his district soon.
Vietnam has suffered most in this outbreak of the avian virus strain known as H5N1. The World Health Organization says that since 2003, at least 112 people have contracted the bird flu in fourth Southeast Asian countries, and 90 of them have been Vietnamese. The majority of human deaths have occurred in Vietnam.
Other cases have occurred in Thailand, Cambodia and Indonesia. Tens of millions of chickens and other birds have died or been culled in Asia because of the virus.
The epidemic devastated Vietnam's chicken farmers last year. The government ordered the culling of chickens in infected areas so they could not pass the virus on to humans, and the economic cost has been estimated at more than 200 million dollars.
What health officials around the world fear most is that the H5N1 virus may change to a form that can spread as easily among people as it now does among poultry. If that happens, health experts say, the result could be as deadly as the 1918 Spanish flu pandemic, which killed between 20 and 40 million people. That virus was a highly infectious avian flu much like H5N1.
H5N1 quickly destroys a patient's lungs. Most flu has a fatality rate of less than five percent, but H5N1 has so far killed half the people who contracted it in Southeast Asia.
U.S. scientists say they have successfully tested a human vaccine against H5N1, but it could be months before it is approved for manufacture and distribution. In the meantime, Vietnam is seeking to control avian flu where it started: in the poultry population.
Veterinarians are fanning out around the country, injecting chickens and ducks with vaccines imported from China. The head of the program, Van Dang Ky, chief of epidemiology at the Ministry of Agriculture, says the goal is to have all chickens vaccinated before the winter flu season starts.
Mr. Ky says he expects to complete the vaccination of 210 million chickens by November. If the program is completed by then, he says, the number of human flu patients will surely be reduced this winter.
Vaccinating chickens will not eradicate the virus, it will only give some poultry immunity. But for a country on the front lines of a potential pandemic, it is considered the best option available, and one that farmers like Mr. Ngu eagerly embrace.
Mr. Ngu says these chickens will be happier if they are vaccinated.
With any luck, the vaccination program will help the virus's potential human victims breathe easier as well.