Title : Comparative efficacy of different H9N2 avian influenza virus inactivated vaccines using some commercially available adjuvants for superior control in broilers
Abstract:
Avian influenza viruses are widely spread worldwide and continue to cause sever economic losses in many countries. The endemic countries including Egypt use different strategies to control the disease including vaccination. There are 3 different AIV serotypes circulating in Egypt which are H5N1, H5N8 and H9N2. Although H9N2 is characterized by being low pathogenic virus versus high pathogenic H5 viruses but this virus still causing continuous problem in broilers specially in combination with continuous circulating infectious bronchitis virus (IBV).
In this paper, we formulate three different inactivated vaccine using the current circulating strain of H9N2 AIV with high antigenic payload using 3 different commercially available adjuvants produced in France and Turkey and compare both efficacy and stability using the international protocol for evaluation of H9N2 AIV inactivated vaccines including serology and reduction of shedding using molecular quantification of viruses twice with 6 months interval for evaluation of formulation stability.
The results showed slight variation (1-3 log 2) in antibodies titres between different formulations as well between first (done just after preparation) and second (done after 6 months storage at 4-8 °C). The reduction in virus shedding results came in parallel with the serology results. In conclusion, the quality of the adjuvant used in preparation of inactivated H9N2 AIV directly affected both efficacy and stability of the vaccine.
