The reason: Fear that they will be used for biological warfare.
Under this little-known policy, North Korea, Iran, Cuba, Syria and Sudan may not get the vaccines unless they apply for special export licenses, which would be given or refused according to the discretion and timing of the U.S. Three of those nations
- Iran, Cuba and Sudan - also are subject to a ban on all human pandemic influenza vaccines as part of a general U.S. embargo.
The regulations, which cover vaccines for everything from Dengue fever to the Ebola virus, have raised concern within the medical and scientific communities. Although they were quietly put in place more than a decade ago, they could now be more relevant because of recent concerns about bird flu. Officials from the U.S. Department of Health and Human Services and the Centers for Disease Control and Prevention said they were not even aware of the policies until contacted by The Associated Press last month and privately expressed alarm.
They make "no scientific sense," said Peter Palese, chairman of the microbiology department at Mount Sinai School of Medicine in New York. He said the bird flu vaccine, for example, can be used to contain outbreaks in poultry before they mutate to a form spread more easily between people.
"The more vaccines out there, the better," he said. "It's a matter of protecting ourselves, really, so the bird flu virus doesn't take hold in these countries and spread."
U.S. Commerce Assistant Secretary Christopher Wall declined to elaborate on the precise threat posed by vaccines for chickens infected with avian influenza, except to say there are "valid security concerns" that they "do not fall into the wrong hands."
"Legitimate public health and scientific research is not adversely affected by these controls," he said.
But some experts say the idea of using vaccines for bioweapons is far-fetched, and that in a health emergency, it is unclear how quickly authorities could cut through the current red tape to get the vaccines distributed.
Under normal circumstances it would take at least six weeks to approve export licenses for any vaccine on the list, said Thomas Monath, who formerly headed a CIA advisory group on ways to counter biological attacks. All such decisions would follow negotiations at a "very high level" of government.
That could makes it harder to contain an outbreak of bird flu among chickens in, say, North Korea, which is in the region hardest hit by the virus. Sudan and Iran already have recorded cases of the virus in poultry and Syria is surrounded by affected countries. Cuba, like all nations, is vulnerable because the disease is delivered by migratory birds.
Kumanan Wilson, whose research at the University of Toronto focuses on policymaking in areas of health protection, said it would be ironic if the bird flu virus morphed into a more dangerous form in one of those countries.
"That would pose a much graver threat to the public than the theoretical risk that the vaccine could be used for biological warfare," he said.
The danger of biological warfare use depends on the specific virus or bacteria. But most experts agree that bird flu vaccines cannot be genetically altered to create weapons because they contain an inactivated virus that cannot be resuscitated.