Highly pathogenic avian influenza in the world: vaccination strategies (review)

Abstract

Avian influenza viruses are epidemiologically dangerous zoonotic pathogens that can cause high morbidity and mortality both in animals and in humans. Reassortment and antigenic shift in the genome of the avian influenza virus draw to a change in its properties: host range, virulence, and other factors. The natural reservoir of avian influenza is wild waterfowl, which can transmit the virus to poultry through the direct contact. The exchange of antigenic sites of viruses occurs over several months in the traditional wintering grounds of migratory birds. Avian influenza viruses with altered genes as a result of reassortment, circulating in wild migratory birds, carry epizootic threat of spread of the disease to the unharmed areas. In this review of highly pathogenic avian influenza there has been analyzed the epizootic situation and possible vaccination strategies that exist in the world. The spatial trend in the spread of highly pathogenic avian influenza in the constituent entities of the Russian Federation was determined using the GIS tool, Median Center in the working environment of the ArcGIS Pro software. Based on the review of selected literature, it has been established that vaccination itself is not considered a solution to the problem. Without monitoring systems, stringent biosecurity and population reduction in case of outbreaks, the control and eradication of the disease is impossible. The decision to vaccinate against avian influenza should be made on a case-by-case basis, weighing all the risks of further spread and mutation of the virus. All industrial poultry enterprises exporting the products must operate in a closed mode and be excepted from the list of vaccination.