Since last year, the current outbreak of highly pathogenic avian influenza (HPAI) has resulted in the killing of nearly 60 million farmed chickens and turkeys, and many epidemiologists and food industry figures believe vaccinating the birds could be the only way to quell the crisis.
Federal policymakers will play a critical role in that inoculation decision.
The Biden administration plans to test a vaccine for bird flu and is mulling whether to mass inoculate commercial poultry flocks, the New York Times reported this week.
A number of vaccines against different strains of bird flu have been developed and tested on flocks in recent years. Vaccinating birds was mandated in China in 2017, according to health organization Gavi, the Vaccine Alliance. These vaccines have shown strong efficacy, said Rodrigo Gallardo, a poultry medicine professor at University of California, Davis.
“In terms of the feasibility of vaccination and how to do it, that’s already proven,” Gallardo said. “It’s more of a political problem.”
But the broiler chicken industry could be the main group standing in the way of the industry embracing immunization.
The HPAI vaccines have not been used on a large scale in the U.S. because of the ramifications the inoculations would have on international trade of chicken products, said Maurice Pitesky, a poultry health and food safety epidemiology professor at UC Davis.
“Vaccination, as we all know from COVID, protects against the disease but doesn’t protect per se against infection,” Pitesky said. “The worry is that the product could spread HPAI around the world.”
Almost 20% of the chicken industry’s profits come from selling their products overseas where there are much stricter regulations on HPAI, the epidemiology professor said, much higher than turkey and egg producers.
The severity of the current outbreak — and fears of it mutating and jumping to humans — could lead to poultry product market decisions to take a backseat. But vaccinating billions of poultry birds, and roughly 300 million egg-laying hens, could prove to be a near impossible task.
“We have to figure out how to thread that needle and think about how much vaccine we can feasibly produce,” Pitesky said.
The egg industry — which has faced significant supply hurdles since the HPAI outbreak began last year — is more receptive to the idea of vaccinating birds, said Kenneth Anderson, a commercial layer flock management professor at North Carolina State University. He said the potential for mass vaccination likely will depend on whether the virus mutates and changes.
“In 2015, we weren’t even considering vaccinations,” Anderson said. “At least this time we’re actually talking about it as a solution.”
Pitesky said the current HPAI outbreak is historic and probably not going to go anywhere for several years because the virus has spread to multiple avian and mammalian species. While the risk of the virus spreading from poultry to humans is low, he said, it could prove unpredictable.
“One of the worries is that nature can cause all kinds of tricks up its sleeve and the more virus we have out there,” Pitesky said, “the more potential we have for something nontraditional to happen.”