Depopulation and biosecurity are the primary means of eradicating avian influenza, but vaccination is an alternative that can be used when these fail.
Vaccination to protect flocks in geographic areas in the U.S. hard hit by avian influenza has been espoused by some poultry veterinarians as an alternative means of working out of the current disease challenge. There is more support for the vaccination alternative in the layer and turkey industries than in broilers, because of these two industries keep their birds longer and tend to have multi-age farms. Breeder companies see improved biosecurity, rather than vaccination, as the most effective means of protecting poultry from avian influenza.
Biosecurity versus vaccination
Jerry Moye, president, Cobb-Vantress, is not a proponent of vaccination; he thinks enhanced biosecurity is a better investment for poultry producers. He said: “If it is a disease that can be eradicated, our choice is always going to be around managing biosecurity and communicating to growers and team members about the importance of their role.” The payoff from enhanced biosecurity isn’t just from avoiding a particular disease; it can also lead to improved bird performance and food safety. “Biosecurity is the stronger program to build. You may be focused on controlling a specific disease like mycoplasma with your biosecurity program, but you are going to have a positive impact on a lot of other diseases and the general health of your birds,” he said.
Dr. Hellen Wojcinski, science and sustainability manager for Hybrid Turkeys, which is part of Hendrix Genetics, said: “Vaccination to provide some protection to valuable genetic stock may become necessary but regions, such as South America, will not accept product originating from flocks which have been vaccinated for any type of influenza. This is not science-based and these restrictions need to be re-evaluated by the importing countries' veterinary service, otherwise poultry companies within these areas may be impacted.”
Geographic dispersion of genetic stock
The current outbreak of highly pathogenic avian influenza that has been spread by migratory birds from Asia to Europe, North Africa and North America is likely to be around for at least a few years, according to disease experts. This is the reality that the world wide poultry industry now faces. Moye said: “We will be dealing with a population of wild birds in our flyways that have a significant amount of avian flu in them and we have to ask ourselves how we better prepare ourselves for alternative sourcing of products so we don’t have interruptions.”
Having grandparent stock placed around the world is a common strategy of primary breeders that might be stretched even further in the future. Dr. Travis Schaal, technical services and regulatory veterinarian, Hy-Line International, said: “Another potential step is strategic placement of additional breeding stock in additional locations to help optimize product security and export capabilities.”
Avian influenza and compartmentalization
The concept of compartmentalization, or establishing that a given operation has taken biosecurity steps which segregate it from disease challenges that may be present in its vicinity, seems custom made for the current worldwide avian influenza challenge. Unfortunately, compartmentalization has not gained much acceptance by governmental bodies.
Wojcinski said: “Compartmentalization is still a work in progress with primary breeders actively moving forward on this initiative. It still requires that trading partners accept the compartment which would allow genetic stock to both enter and exit a region where highly pathogenic avian influenza is occurring.”
Dr. Alberto Torres, export manager, for Cobb-Vantress, said that he has seen a shift in USDA from being skeptical of the concept of compartmentalization to the agency becoming an advocate for it. He reports that breeding companies are still working on a plan with the USDA for establishing compartments in the U.S. Torres said that they are probably still a year away from when companies can apply to have operations recognized as compartments.
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