BACKGROUND Vaccines constitute a unique selective pressure, different from natural selection, drives the evolution of influenza virus. In this study, A/Chicken/Shanghai/F/1998 (H9N2) was continually passaged in specific pathogen-free embryonated chicken eggs with or without selective pressures from antibodies induced by homologous maternal antibodies. Genetic mutations, antigenic drift, replica...

Abstract Background and Aims: Vaccination of poultry has a major impact on the prevention and control of avian influenza viruses. Nanobiotechnology techniques provide a new approach for improvement of influenza vaccine efficacy. In this study, efficacy of an inactivated nano-adjuvant vaccine developed based on an endemic H9N2 virus was evaluated in SPF chickens. Materials and Methods: I...

Background and Aims: Avian Influenza (AI) H9N2 subtype was first reported to infect turkeys in the United States in 1966 and has been panzootic in Europe and Asia. The impact of avian influenza caused by H9N2 viruses in Iran is now significantly more severe than in previous years. Methods: Sequence analysis and phylogenetic study of the complete coding region Polymerase A (PA) gene of H9N2 subt...

The interest in broad-range anti-influenza A monoclonal antibodies (mAbs) has recently been strengthened by the identification of anti-hemagglutinin (HA) mAbs endowed with heterosubtypic neutralizing activity to be used in the design of "universal" prophylactic or therapeutic tools. However, the majority of the single mAbs described to date do not bind and neutralize viral isolates belonging to...

A simple molecular technique for rapid genotyping was developed to monitor the internal gene composition of currently circulating influenza A viruses. Sequence information from recent H1N1, H3N2, and H5N1 human virus isolates was used to identify conserved regions within each internal gene, and gene-specific PCR primers capable of amplifying all three virus subtypes were designed. Subtyping was...

Active serologic surveillance is necessary to control the spread of the avian influenza virus (AIV). In this study, we evaluated a commercially-available cELISA in terms of its ability to detect AIV antibodies in the sera of 3,358 animals from twelve species. cELISA detected antibodies against reference H1- through H15-subtype AIV strains without cross reactivity. Furthermore, the cELISA was ab...

abstract background and aims: vaccination of poultry has a major impact on the prevention and control of avian influenza viruses. nanobiotechnology techniques provide a new approach for improvement of influenza vaccine efficacy. in this study, efficacy of an inactivated nano-adjuvant vaccine developed based on an endemic h9n2 virus was evaluated in spf chickens. materials and methods: in each t...

background and objectives: a number of different subtypes of avian influenza (ai) viruses have emerged in humans includingh5n1, h7n2, h7n7 and h9n2. these influenza viruses are excreted in the infected birds and in their respiratory secretions.the aim of this study was to investigate seropositivity against h9n2 and h7n7 viruses among poultry and slaughterhouse workers with occupational risk of ...

High-pathogenic avian influenza viruses (HPAIVs) evolve from low-pathogenic precursors specifying the HA serotypes H5 or H7 by acquisition of a polybasic HA cleavage site. As the reason for this serotype restriction has remained unclear, we aimed to distinguish between compatibility of a polybasic cleavage site with H5/H7 HA only and unique predisposition of these two serotypes for insertion mu...

Virus H9N2 has become the most common subtype of low pathogenic avian influenza (LPAI) in poultry and shows ability to infect humans. One important factors triggering virus ​​pandemic is live bird market (LBM). The acts as an internal gene donor other subtypes, such H5N1, H5N2, H7N9, H10N8, This study was conducted detect presence molecular characteristics hemagglutinin fragment at cleavage sit...