Abstract
Vaccination against highly pathogenic avian influenza (HPAI) viruses, along with other measures, was successful in eradicating AI in very few countries where the competence of national veterinary services or the geography and bird density have contributed favorably to the outcome. The main constraints to an effective AI vaccination are vaccine composition matching field strains, reliable cold chain and logistics to target all poultry smallholders, constraints related to the availability of sufficient financial and human resources. When not conducted properly, vaccination can also contribute to the emergence of new field viral strains, through genetic drifts of HPAI viruses. While new technologies have improved the possibility to produce high quality vaccines matching field strains, recurrent issues like post-vaccination field surveillance and vaccination coverage continue to limit the relevance of AI vaccination in smallholder settings. A "game-changer" vaccine targeting smallholders should be universal to protect against all field viral strains and reduce significantly, if not totally eliminate, the need for costly post-vaccination surveillance. The ease of administration of this vaccine (eye drop or one single injection) would further contribute to its relevance in the field. These characteristics are considered essential for the product profile of an AI vaccine that can contribute in a meaningful way to the livelihoods of poultry smallholders.
Highlights
More than 30 epizootics of high pathogenicity Avian Influenza (HPAI) have been reported in poultry (Gallus domesticus) and other birds since 1959, vaccination of Poultry has only been added as a control tool since 1995 (Swayne et al, 2014)
AI viruses in poultry are classified as either low pathogenic (LPAI) or highly pathogenic (HPAI), based on the clinical signs and mortality, using the definition established by the World Organization for Animal Health (OIE, 2018)
As a virus is transferred from wild birds to poultry, natural selection within the host favours greatly adapted strains, which often become more pathogenic for both LPAI and highly pathogenic avian influenza (HPAI) pathotypes (Swayne et al, 2013)
Summary
Citation for published version: Peters, A & Guyonnet, V 2020, 'Are current avian influenza vaccines a solution for smallholder poultry farmers?', Gates Open Research.
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