Isolation And Identification Of Avian Influenza Virus H9 Subtype (Chongqing Strain) And Research Of Vaccine

Avian Influenza virus (AIV), which is the pathogen of Avian Influenza (AI), caused an acute, highly contagious disease, resulting in enormous economic losses of the poultry industry. In recent years, despite a lot of national human and financial resources were put into preventing and controlling the avian influenza virus, human and avian infection continue to occur and there is a rising trend year by year. The threat of Avian flu on public health and the threat of life and property of people becomes more and more serious, effective control of avian flu becomes a pressing problem.Infected birds are the source of the prevalence of the avian influenza, many people infected due to have come in contact with the sick chicken. Therefore, effective control of the occurrence of avian flu, is not only good for the poultry industry, but more important to reduce the human infection chance. It's the most direct and effective way to control of human and bird flu infection.Avian Flu Virus is well known for their propensity to easily mutate over time and space, which is the reason that the prevention of the virus is difficult. There is no current cure for the flu. Progress in therapeutic anti-flu drug development is very slow. The medicine can be used for curing flu are few and limited. Vaccination against influenza is the primary means of prevention and control of avian influenza. The vaccine can significantly reduce the virus survived in the animals and the environment. Vaccination is a major prevention and control measure against bird flu.In this study, the virus was isolated from sick hen in a large layer farm. Which infected avian flu. The hemagglutination (HA) titer of the viral strain reached 9lg₂. Hemagglutination inhibition (HI) test with the standard serum of avian influenza H9, H7, H5 and Newcastle disease virus respectively, showed that hemagglutination could be inhibited by H9 subtype of avian influenza standard serum. Initially, the strain was identified as H9 subtype avian influenza virus. After viral RNA extraction, reverse transcription of the viral RNA into cDNA template, and PCR amplification of M protein, NA protein, H9 subtype gene of avian influenza virus were completed. All the target bands were amplified, which is further identified as avian influenza H 9N2 subtype. Oil emulsion adjuvant vaccine was prepared with the inactivated strain virus as the antigen. Animal experiments showed that the oil emulsion adjuvant vaccine can effectively control the virus attack, and is a good prevention of the local farms against avian flu. Compared with the vaccines currently on the market, vaccination with this inactivated strain virus as the antigen, had strong immunogenicity, which showed that this strain is a fine potential vaccine candidate strains.