In the US, poultry vaccinations may focus on egg-drained chickens, as opposed to broiler chickens raised for meat. During the current outbreak, more than 77% of the affected domestic poultry were egg-laying hens. In a USDA press release, Rollins said the agency is considering a “targeted and thoughtful strategy” for vaccinations.
But the broiler chicken industry is worried that even targeting vaccinations for laying chicken will hurt the US, the second largest exporter of chicken. Ashley Peterson, senior vice president of science regulation at the National Poultry Council, says other countries are likely to ban all U.S. poultry products, even if the US only vaccinates spawning hens. “When you move to a vaccine, you say the virus is essentially endemic, and this is how we deal with it,” she says. “We prefer not to deal with the virus. We want to eliminate it completely.”
The organization supports USDA’s current policy to cull infected herds, as well as increased biosecurity on farms. Measurements include isolating newly acquired animals, wearing protective clothing in chicken homes, disinfecting footwear before entering the animal area, and cleaning agricultural equipment.
But Carol Cardona, a professor of bird health at the University of Minnesota School of Veterinary Medicine, says biosecurity alone is unlikely to eliminate avian influenza. “Farmers are already doing everything they can and are very tired of hearing about biosecurity,” she says. “Without detailed information about how those birds are infected, it’s extremely difficult to properly target biosecurity.”
This virus can be carried inside and outside the chicken barn of shoes, clothing and equipment that move inside and outside the chicken barn. Mice, rats and other small mammals can also carry the virus.
Cardona said the disease is currently so widespread that it will require multiple strategies to reduce the outbreak. “We’ve been fighting this battle with one hand tied behind our backs. I think there are other tools,” she says. “We need to create a new way to keep it out, and some of that will involve vaccinating it.”
Even if vaccinations don’t always prevent infection, Lorenzoni says it can help reduce the amount of virus circulating in the environment.
And trade disruptions may be short. Rollins said the USDA will work with its trading partners to limit the impact of exporting trade markets from potential vaccinations. Lorenzoni says there is pressure from other markets to keep international exchanges of poultry viable. “Everyone has the greatest benefit to move as fast as possible with these commercial contracts,” he says.
