Federal health officials announced plans Monday for a second vaccine to protect people from bird flu because the virus that is spreading among birds in Asia and Europe has changed significantly in the past year.
The government has several million doses of an earlier bird flu vaccine, but it was based on a sample of virus taken from Vietnam in 2004. The germ is believed to have mutated enough since then that the form now circulating in Africa and Europe may be different, health officials said.
U.S. Health and Human Services Secretary Mike Leavitt said Monday he had authorized the National Institutes of Health and the federal Centers for Disease Control and Prevention to begin working on a second vaccine for humans.
“In order to be prepared, we need to continue to develop new vaccines,” Leavitt said at an immunization conference in Atlanta.
The World Health Organization has reported at least 174 human cases of bird flu, including 94 deaths since 2003.
So far, most if not all of the human victims were in very close contact with infected birds, but health officials worry that as bird flu spreads, it could mutate into a strain that easily passes among people.
Dr. Margaret Chan, who is spearheading the WHO efforts against the virus, said it poses a greater challenge to the world than any previous infectious disease. Since February, the virus has spread to birds in 17 new countries in Africa, Asia, Europe and the Middle East, Chan said.
Poland on Monday confirmed its first outbreak of the disease, saying laboratory tests found that two wild swans died of the lethal strain.
Several cats have also tested positive for the deadly strain in Austria’s first reported case of the disease spreading to an animal other than a bird, officials in that country said Monday. A dead cat in northern Germany was found to have the virus last week.
The WHO has played down the threat to human health from infection in domestic cats, but the news has alarmed pet-loving Europeans and made headlines across the continent. It is thought that cats are getting the virus by eating infected birds.
The WHO describes bird flu as unprecedented in its scope as an animal disease, saying it is costing the world’s agriculture industry more than $10 billion and affecting the livelihoods of 300 million farmers.
Fears of infected meat
Health experts stress there is no risk from eating properly cooked meat, but fears over the virus have dented consumption.
France, which has Europe’s largest poultry industry, has said it is losing $48 million a month after an outbreak of H5N1 at a poultry farm. The news led more than 40 countries to impose curbs on French poultry products, including foie gras.
France announced a new case of H5N1 in a wild duck in the east of the country on Sunday, while another test on a wild swan showed the virus had spread several hundred km (miles) south to the Mediterranean Bouches-du-Rhone area.
U.S. Agriculture Secretary Mike Johanns said on Saturday the United States was preparing for an outbreak of avian flu and assured consumers that poultry remained safe to eat.
“There is no way to put a big cage around the United States. I think it is fair to assume we’ll deal with ... avian influenza,” said Johanns. “We could see it in domestic flocks as well as (wild) birds.”