The biology of avian influenza virus: a comprehensive review with insights into novel therapeutic strategies

Avian influenza, commonly referred to bird flu, is a severe infectious respiratory disease affecting millions of birds each year that causes extensive losses in the poultry industry and risks human health. Avian influenza causes substantial economic losess to the poultry industry, as outbreaks of highly pathogenic avian influenza (HPAI) can severely impact poultry populations, necessitate the culling of infected birds, and impose significant financial burdens. Zoonotic infections can lead to significant morbidity and mortality, underscoring the economic and public health consequences of influenza. The pathogenicity of influenza viruses is a consequence of two factors: the virus's contagiousness via direct contact and aerosol transmission and its existence as a quasispecies. Annual vaccination is the fundamental preventative strategy for influenza. Due to the rapid evolution of influenza viruses through antigenic drift and antigenic shift, it is necessary to update vaccines annually to correlate with the most prevalent field strains. To overcome the limitations of the present influenza vaccine program, there is a critical need for effective anti-influenza therapies. The majority of presently approved drugs exhibit limited efficacy and are liable to rapid development of resistance. Consequently, it is imperative to investigate novel treatment alternatives. As a result, the key characteristics of avian influenza were discussed in this review, along with novel approaches that exhibit promising activities against the virus.