Bird flu vaccine may be too late for pandemic
Drug companies may not be able to produce enough bird flu vaccine in time to combat a human pandemic, a top United Nations official said on Tuesday as governments scrambled to contain the deadly virus.
It could take six months to manufacture adequate vaccine stocks, and current stockpiles may be useless because the flu virus has mutated, said David Nabarro, U.N. coordinator for global readiness against an outbreak.
He said “very high priority” efforts were under way to raise manufacturing capacity so that a vaccine could be produced more quickly once a virus emerged that could cause a pandemic.
Experts say the virus is mutating steadily and there are fears that if it takes a form which spreads quickly among humans it could kill millions.
“We do not know what the genetic makeup of the eventual mutant virus will be, therefore we cannot be sure that existing vaccines that have been stored up will be effective,” Nabarro said.
Outbreaks of bird flu at the weekend in Romania and Turkey triggered fears that the highly contagious disease could advance into Europe.
Experts there have not yet determined whether the cases are from the highly pathogenic H5N1 virus, which has killed millions of birds and 65 people in Asia since 2003. Officials have played down the likelihood.
Romanian authorities said on Tuesday they had found no new cases of avian flu but would continue culling poultry in the Danube delta near the Black Sea to prevent the disease from spreading.
Bird Flu Prevention and treatment
Avian influenza in humans can be detected with standard influenza tests but these tests have not always proved reliable. In March 2005, the World Health Organization announced that seven Vietnamese who initially tested negative for bird flu were later found to have carried the virus. All seven have since recovered from the disease.
Antiviral drugs are sometimes effective in both preventing and treating the disease, but no virus has ever been really cured in medical history. Vaccines, however, take at least four months to produce and must be prepared for each subtype.
SUSPECT CASES
Three ducks, which tested positive for bird flu on Friday, remain the only birds in which disease antibodies have been detected. But Romanian officials said testing of suspect cases would go on with the help of European Union experts.
“There was no other positive case,” Agriculture Ministry spokesman Adrian Tibu said.
He said EU experts were helping local scientists isolate the virus and would send samples to Britain to discover whether they are dealing with the H5N1 strain.
Avian influenza
Also called fowl plague, avian flu, and bird flu. A highly contagious viral disease with up to 100% mortality in domestic fowl. Caused by influenza A virus subtypes H5 and H7. All types of birds are susceptible to the virus but outbreaks occur most often in chickens and turkeys. The infection may be brought by migratory wild birds which can carry the virus but show no signs of disease. Humans are only rarely affected.
Type A influenza viruses can infect several animal species aside from birds, including pigs, horses, seals and whales. Birds are an especially important species because all known subtypes of influenza A viruses circulate among wild birds, which are the natural hosts for influenza A viruses. Avian influenza viruses do not usually directly infect humans or circulate among humans.
Results of British laboratory tests are expected by the end of the week.
Turkey warned that it faced a high risk of further outbreaks of avian flu as it lies in the path of many species of migrating birds, which can carry the virus long distances.
The 25-nation European Union, along with a number of other countries, banned imports of birds from Turkey on Monday.
France called on Tuesday for European Union health and foreign ministers to meet soon to coordinate their reaction to the spreading bird flu virus.
“We can see that the H5N1 virus, this bird flu virus, is spreading and is arriving at our doors,” French Foreign Minister Philippe Douste-Blazy said on France 2 television.
A European Commission spokesman said EU health ministers would meet informally on October 20-21.
In Bulgaria, authorities said on Tuesday they were testing three birds found dead in the north of the country but so far there were no indications the virus had crossed its borders. Test results were expected in about a week.
Egypt banned imports of live birds and tightened up quarantine controls at airports. It also canceled the annual bird-hunting season to minimize contacts between hunters and the migrant birds they shoot.
The United Arab Emirates banned imports of live birds and feathers from Turkey and Romania, and Saudi Arabia, the Gulf region’s biggest economy, said it had prepared an emergency plan to ban imports from any country where an outbreak of bird flu had been confirmed.
Revision date: July 7, 2011
Last revised: by Andrew G. Epstein, M.D.