OCEAN CITY, Md. — Vaccines could help the U.S. contain its avian influenza outbreak, but there’s little excitement about using them.
Vaccination, even on a limited scale, could devastate the U.S.’ $6 billion poultry export business.
“We don’t have any assurance that any of our trading partners would accept our products if we began vaccinating any birds,” said Julie Gauthier, assistant director for poultry health at USDA Veterinary Services.
Gauthier spoke Oct. 4 at the National Meeting on Poultry Health, Processing and Live Production presented by the Delmarva Chicken Association.
Vaccination protects birds from serious illness and death from avian influenza. But it also makes the disease difficult to detect, and countries don’t want to risk accidentally importing a virus as destructive as avian influenza, according to the World Organisation for Animal Health.
Vaccinated birds may not show clinical signs if they get infected with avian influenza, and both vaccinated and infected birds have antibodies against the virus.
The latter challenge can be overcome by using a vaccine based on a different flu strain than the one of concern, and by using a test that distinguishes between the antibodies related to the two strains, according to Epizone, a European veterinary research group.
Still, such a surveillance program would have to be robust, and it would cost more than the current testing strategy, Gauthier said.
The short-term response to U.S. vaccination would be severe.
Many Asian countries would likely block poultry exports from the entire U.S., and other countries would demand attestation that exported products were not from vaccinated birds, said Garrett Borkhuis, director of trade and technical services at the USA Poultry and Egg Export Council.
Those restrictions would jeopardize sales of the nearly 18% of U.S. broiler production that is exported, which includes chicken feet shipped to China and dark meat to Asia and Mexico.
Since its last major avian influenza outbreak in 2015, the U.S. has gotten many trading partners to reduce the amount of the country covered by their poultry bans.
“They’ve gotten many countries that were once nationwide bans to state level, and they’ve gotten others that were at state level down to county level or even 10-kilometer level,” Borkhuis said.
In 2015, almost 20 countries, including major markets like China and South Korea, imposed bans on poultry from the whole U.S. This year only Qatar, Malaysia and Namibia — minor trading partners all — have made such expansive restrictions, he said.
With the push toward regionalized bans, direct export losses from avian influenza have been limited to $272 million through July, compared to $1.3 billion in 2015. And even with the trade restrictions, the U.S. is expected to set a record for poultry exports this year, Borkhuis said.
The U.S. developed an avian influenza vaccine bank during the previous outbreak. But infections ended before the vaccines could be used, and when the stockpile expired, it had to be discarded at great expense.
If the U.S. wanted to secure avian influenza vaccines now, it would reserve an order with manufacturers.
“We would get to the front of the queue on their production, and then they would agree to provide us so many doses,” Gauthier said.
Granted, the U.S. would only start vaccinating against avian influenza if the poultry industry showed interest, and that would probably only happen in a last-ditch situation.
“It would need to get so bad that it would be a tool that helps you produce products and birds,” Gauthier said.
Negotiating Bans
Though the U.S. is a major importer of goods, it’s unlikely to use that market power to swing a deal on poultry vaccination.
The U.S. wants to be a model for basing trade rules on science rather than politics, and poultry is a small enough export sector that other industries will object if their trade opportunities are linked to it.
“We won’t be able to swap truck tires for poultry,” said Dawn Hunter, trade policy adviser for USDA Veterinary Services.
Even so, other countries can be slow and seemingly capricious about removing trade restrictions once they have been implemented. Borkhuis said the U.S. needs to revise its bilateral trade agreements to clarify how poultry bans will be dropped.
On that point, the U.S. actually prefers handshake arrangements rather than formal accords, Hunter said.
Such an agreement would lock the U.S. into scientific protocols that could become outdated, and reopening the trade deal would invite other countries to propose a raft of additional requirements, Hunter said.
In the current outbreak, USDA is already having trouble distributing all of the epidemiological information it agreed to provide to other countries.
The U.S. would like to not add any more countries to its list of recipients, but that’s difficult.
“Each country goes, ‘Well, you provided that information to Japan, so you should be able to provide it to the Philippines,’ or whatever the case may be,” Hunter said.
With vaccines out of favor, the U.S. plans to continue fighting avian influenza with biosecurity around poultry, and destruction of the virus on farms where it appears.
