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Background: In the last decade H9N2 avian influenza viruses had caused outbreaks in poultry in many parts of the World. This subtype could infect other animals such as human and pig. Avian H9N2 virus has acquired receptor binding characteristics typical of human’s strains, increasing the potential for reassortment in both human and pig respiratory tracts. This indicates that the A/H9N2 would be a potential threat to human population.Objectives: The aim of this was to indentify the presence of A/H9N2 virus among different high risk occupational groups, in Tehran and Qazvin provinces in seasonal outbreak in Iran.Material and Methods: 182 sera were collected from the poultry farms and slaughterhouse workers, and animal vaccinators and also veterinarians in seasonal outbreak (December 2010, January 2011 and July 2011). Hemagglutination Inhibition (HI) and ELISA assays were performed to detect anti-H9 antibody. Sera adsorption was performed to eliminate cross-reactivity between anti-H3 and anti-H9. In HI test the titer ≥20 was considered to be positive.Results: Only 3 (1.64%) in HI that showed titer ≥ 20 and 21(11.53%) sera in ELISA showed OD > 0.7 were assumed positive for H9 virus infection.Conclusions: The findings of this study show that H9N2 avian influenza virus can infect human. Repeated interspecies transmission H9N2 viruses from poultry to human raises concerns about adapting of this subtype with new host

Background and Aims: Influenza vaccination is one of the best way to prevent and control influenza worldwide. It is manufactured by WHO-licensed companies based on the WHO expertise committee annually. The aim of this study was partial quality control of the commercial human influenza vaccine 2008-9 and its matching with the circulating strains. Materials and Methods: The trivalent imported vaccine was cultured in bacterial and fungal media, injected to the mice and inoculated into the allantoic cavity of Embryonated Chicken Eggs (ECEs). Hemagglutination-Inhibition (HI) assay was carried out on pre and post vaccination serum samples. The bacterial endotoxin was assessed by LAL assay. The Hemagglutinin (HA) content of the vaccine was measured using SRID. Heterogenecity of the circulating influenza strains during 2008-9 seasons in Tehran in comparison to the vaccine strains was determined. Results: No bacterial contamination and no occurrence of mortality and morbidity in animal was observed. The mean fold increase of HI antibody titer in subjects without previous vaccination for H1N1, H3N2 and B strains were 6.7, 3.3 and 1.8 respectively, while in subjects with previous vaccination were 4, 1.6 and 1.1 for same strains. Amino acid variation was found in Tehran H1N1 isolates but the H3N2 isolates showed higher genetic resemblance to the 2008-9 vaccine strain. Conclusion: The sterility, safety, and efficacy of the vaccine were approved and there was some variation in A/H1N1 but not in A/H3N2 isolates in comparison with the vaccine strain.