بررسی بهینه سازی آزمایش کارآیی واکسن غیر فعال انفلوانزای طیور تحت تیپ ‭H9N2‬

Avian influenza AI (H9N2) subtype known as non-highly pathogen, however, causes sever clinical signs and high mortality in commercial chicken flocks in Iran. Because of non-highly pathogen nature of the virus, it is not possible to practice efficacy test for the commercial H9N2 vaccines. In this study an efficacy test was developed for H9N2 vaccine. Optimized co-infection of H9N2 and Escherichia coli could cause 30% mortality rates among SPF chickens. Sixty five 10-day-old SPF chickens were divided in two groups. The first group was vaccinated with a commercial inactivated AI vaccine and then challenged with H9N2 and Escherichia coli at 38 and 41 days old, respectively. The remaining chickens were kept as control group. No clinical signs, mortality and virus excretion were observed among vaccinated chickens whereas, depression, coughing, sneezing, gasping, virus excretion along with 20% mortality rates was observed in control group. Pathological signs were included tracheal exudates, with occlusion of bronchi and bifurcation of the trachea by fibrinonecrotic casts resulting asphyxia. It seems that co-infection of H9N2 and Escherichia coli method is a new and reliable efficacy test for H9N2 vaccine.

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آنفلوآنزاویروس ، طیور ، واکسن(ها) ، کارایی