By any measure, the attempts by USDA-APHIS to eradicate Highly Pathogenic Avian Influenza have been an abject failure.  In any event, it is an epidemiologic reality that it is impossible to eradicate an endemic disease with wild avian and mammalian reservoirs.  Rapid diagnosis, depopulation, disposal and decontamination are effective and appropriate approaches to an introduction of an isolated exotic disease. Since 2020 and possibly prior to this time, the current approach relying on variable levels of biosecurity cannot protect flocks.  With the emergence of bovine influenza-H5N1, the situation has become more complicated.  It is now evident that close to 170 diagnosed herds affected by H5N1 in 13 states represents the potential for transmission to large egg-production complexes.

Last week, the USAPEEC, the National Chicken Council, the National Turkey Federation, United Egg Producers and USPOULTRY submitted a joint letter to the Secretary of Agriculture expressing concern over HPAI and seeking “novel methods to prevent, detect and respond to this virus.” At this time, a logical and appropriate but belated initiative.  The letter included the phrase “novel methods to prevent” HPAI. Given that the approach by USDA is entirely reactive  something “novel” beyond biosecurtity is required. But then we come to the “V’ word that shall not be uttered! The letter expressed the need to “preserve all U.S. export markets for poultry products” evidently a manifestation of the inherent conflict among the associations concerning vaccination. The communication did however refer to “conducting important research, particularly as it pertains to vaccines”. As far as assessing combinations of biosecurity with vaccination, “important research” especially in the laboratory is a delaying tactic since there is adequate field evidence of efficacy. What is needed is a USDA supervised field evaluation following the successful implementation for the  foie gras industry in France. A suitable U.S. candidate would be Weld County CO. USDA has recorded seven cases among four complexes in 30 months with one farm affected three times and a second twice, suggesting epidemiologic factors contributing to regional endemnicity..

The problem is that the U.S. producers and specifically the broiler segment are justifiably concerned over potential loss of export markets as a result of introducing a controlled vaccination program.  This restraint should be critically reviewed.  The bulk of our low-price leg quarters are destined to nations that either have endemic HPAI or are probably willing to accept an APHIS certification program based on PCR assay. This innovation would certify that flocks of origin destined for export are free of infection prior to slaughter and shipment.  Nations that are unwilling to accept appropriate documentation and that persist in imposing unrealistic, anachronous and unjustified embargos against the U.S. to protect their domestic industries are probably not prospects for export.

While the export impasse prevails, egg production and turkey producers are experiencing losses beyond the previously limited fall and spring migration periods. This is especially the case in regions with a high concentration of production involving these two segments of U.S. production.

It is not necessary to conduct ‘research’, there is adequate published information available as to the effectiveness of commercially available vaccines in reducing the incidence of outbreaks and facilitating control of the disease. 

The zoonotic implications of H5N1 is evidenced by workers involved in depopulation of an infected egg complex in Colorado with a prevalence rate yet to be determinedwhen investigations have been completed. Affected individuals displayed not only conjunctivitis but also respiratory symptoms and malaise. This is consistent with the acquisition by the avian H5N1 virus of a mammalian adaptation marker E627K indicating that the original avian virus isolated from dairy cows and human contacts is now more infectious and pathogenic for humans.  Introduction of H5N1 virus onto egg production complexes with upwards of two million susceptible hens creates the potential for mutations, some of which may result in emergence of a zoonotic strain that may even become contagious.

The letter addressed to APHIS presents a ‘chicken or an egg’ dilemma.  The emphasis was placed on USDA to engage with trading partners to obtain commitments to accept U.S. exports in the event of introducing a controlled vaccination program. If we wait for assurances from a number of trading partners, as a pre-requirement for vaccination, we will continue to depopulate egg production and turkey farms ad infitinum.

Vaccination is now accepted by the World Association of Animal Health as a component of a broader strategy including biosecurity to suppress avian influenza. The question of vaccination may well pass beyond the purview of USDA if a zoonotic strain emerges or if a recombinant event results in the emergence of a pandemic strain of influenza incorporating avian genes.

During the 1970s, the world’s poultry industries were faced with velogenic viscerotropic Newcastle disease.  The infection was effectively controlled by vaccination.  Avian influenza is ‘the Newcastle disease of the 2020s’ and should be approached with a similar mindset that existed half a century ago.

The letter from the poultry organizations is a first step and clearly indicates a willingness to consider vaccination to preserve flocks and herds and to avert a possible U.S. epidemic or a worldwide pandemic of H5N1v influenza among susceptible human populations.