This past week, the USDA-Animal Health and Plant Inspection Service (APHIS) lifted trade restrictions on live poultry from France, provided these flocks were not vaccinated against HPAI. The release indicated “The U.S. can maintain safe trade with fewer restrictions on poultry from unvaccinated flocks that aligns with World Organization for Animal Health (WOAH) guidelines.” This is a self-serving misstatement of WOAH policy.  The Organization accepts vaccination as an adjunct to biosecurity to control avian influenza.

The restriction on importation of live poultry and products from vaccinated flocks is based on the premise that “birds may not show symptoms potentially leading to the export of infected animals or contaminated products”.  Emphasizing the distinction between products from vaccinated and unvaccinated flocks is intended to reinforce the U.S. policy of withholding vaccination from the segments of the industry most affected by species susceptibility and location.

The comment that “vaccinated birds may not show symptoms potentially leading to export of the infected animals or contaminated products” is valid but in the context of available technology is a fallacy bordering on sophistry.  In the age of PCR, it is possible to certify that a flock or a number of flocks intended for export as a consignment were free of avian influenza at the time of harvest.  Differentiating between infected and vaccinated flocks is also possible using available DIVA vaccines.  APHIS is following the lead of King Canute, the medieval Anglo-Saxon ruler who believed he could command the tides to recede, but he ended up with a wet perineum.  The APHIS is not controlling HPAI as evidenced by the incidence rate and magnitude of losses due to HPAI. Infection is clearly endemic to North America and is characterized by seasonal outbreaks associated with the migratory movement of waterfowl.

Apart from the reality that USDA has failed in their attempt to either control or eradicate HPAI based on a slaughter-out policy, expenditure on indemnity and logistics is draining the resources of the Commodity Credit Corporation. Drawing on this bottomless piggy bank to support an ineffective program is probably illegal use of funding.  The public sector expenditure pales in comparison to the immense cost to consumers of high-priced eggs, reflecting the disequilibrium between supply and demand.  During the 2015 epornitic consumers paid approximately $2 per dozen more for seven billion dozen eggs than they would have in the absence of depopulation due to HPAI amounting to an estimated $15 billion.  The cost in 2024 is considerably higher given the wider differential in shelf price driven by a five percent reduction in the producing flock.

Vaccination against avian influenza is not a panacea and will require continued biosecurity and ongoing surveillance to support exports. Immunization is accepted by the World Organization of Animal Health as an adjunct to biosecurity procedures to control HPAI. Immunization is applied with evident epidemiologic and economic benefits to reduce the incidence rate of HPAI in specific segments of the world poultry industry.  Adoption of preventive vaccination for U.S. egg production flocks, commercial turkeys and possibly breeders in areas with a history of outbreaks should be considered as a modification of current APHIS policy. Withholding vaccination as a component of an integrated program responding to an endemic disease spread by deficiencies in biosecurity and by aerogenous route will perpetuate the disease. The longer HPAI persists in withholding immunization of U.S. poultry populations the greater will be the probability of an emerging zoonotic strain with potential for contagion.