Evaluation of neutralizing antibody on vaccinated chicken by gamma irradiated Avian Influenza vaccine subtype H9N2

Avian influenza A subtype H9N2 virus belongs to Orthomyxoviridae family and causes low-pathogenic disease. H9N2 subtype was first reported to have infected turkeys in the United States in 1966 and has been enzootic in Eurasia. In Iran, the H9N2 virus was first isolated from broiler chickens in 1998 in Ghazvin Province and it is the most prevalent subtype of influenza virus in poultry industry in Iran at the present timecausing serious economic losses in the poultry industry. The hemagglutinin (HA) antigen is the most important viral glycoprotein for attachment and fusion in virus replication cycle and is highly immunogenic.The aim of this research is evaluation of neutralizing antibody on vaccinated chicken by gamma irradiated Avian Influenza vaccine subtype H9N2.Methods and MaterialsAvian Influenza virus (AIV) subtype H9N2 was multiplied on embryonated SPF chicken eggs of 9–11 days. AIV was irradiated by a Nordian model 220 gamma cell instrument at a dose rate of 2.07 Gy/s and activity of 8677 Ci to damage influenza virus genomic RNA to inactivate virus infectivity with 30 kGy gamma radiation. The neutralizing antibody response by hemoggluationinhabition (HI) method wasevaluated on vaccinated broiler chickens in three vaccine concentrations (1, 10-1, and 10-2). The result of antibody titers wasanalyzed by Anova one-way method.ConclusionThe result ofantibody titration by HI methodwas shown inhibition of erythrocyteaglutination by an antigen-antibody reaction was increase significantly for two vaccinated groups (1 and 10 -1 vaccine concentrations) against negative control group (P<0.05).

Keywords:

Avian Influenza A subtype H9N2 virus , Gamma Irradiation , Hemagglutinin Antigen , Inactivation , HemoggluationInhabition test , Broiler Chicken