A new inactivated bivalent vaccine, Mefluvac H9+ND7 0.3, which combines the avian influenza (AI) H9N2 (2016 strain) and recombinant Newcastle Disease virus (NDV) genotype VII (2017 strain), has shown promising results in endemic regions.
Avian influenza H9N2 and NDV genotype VII pose significant threats to the global poultry industry, leading to considerable economic losses through increased mortality rates and lowered productivity. This situation has led to the adoption of the novel inactivated bivalent vaccine, aimed at addressing these prevalent viral challenges. A recent study was conducted to assess the vaccine’s safety, immunogenicity, and protective efficacy in a controlled environment.
Methodology and Materials
A total of 2,000 healthy, antibody-negative chickens aged 3-4 weeks were selected for this study. The birds were divided into two groups: one vaccinated group of 1,500 chickens received a single 0.3 mL dose subcutaneously, while the remaining 500 chickens formed a non-vaccinated control group. All birds were provided with commercial feed and had unrestricted access to water and multivitamins for immune support before and after vaccination.
Prior to vaccination, blood samples were taken to confirm negative antibody titers (≤2 log₂) against both NDV and AI H9N2, employing the Hemagglutination Inhibition (HI) method. The immune response to the vaccine was evaluated through serological tests conducted at 21, 28, and 60 days post-vaccination. Additionally, a challenge test using NDV GVII strain was performed on 200 vaccinated and 100 control chickens at 21 days post-vaccination, while the immune response against AI H9N2 was monitored serologically for a longer duration without a challenge test.
Results
The findings demonstrated a robust safety profile for the vaccine, with no adverse reactions or mortality observed, and no significant impact on weight gain in the vaccinated birds throughout the study period. Serological evaluations revealed consistent antibody responses post-vaccination. In the vaccinated group, NDV GVII HI titers averaged 6.99 log₂ at 21 days and 5.87 log₂ at 28 days, while AI H9N2 titers reached 7.01 log₂, 6.17 log₂, and 6.07 log₂ at 21, 28, and 60 days post-vaccination, respectively.
Conversely, the control group remained seronegative throughout the observation period. The challenge study further confirmed the vaccine’s protective efficacy: all 200 vaccinated chickens maintained their health upon exposure to NDV GVII, whereas the control group experienced complete mortality.
Conclusion
This study validated that Mefluvac H9+ND7 0.3 is safe, exhibits high immunogenicity, and provides complete protection against NDV GVII challenge. The vaccine sustained substantial antibody titers against both low-pathogenic avian influenza H9N2 and Newcastle Disease throughout the observation period. By integrating two recently isolated strains into a single formulation, this vaccine offers poultry producers a practical solution that streamlines operations, reduces handling stress on birds, and ensures dual protective benefits. These findings underscore the significance of Mefluvac H9+ND7 0.3 in enhancing poultry health management.
References are available upon request.
To learn more about vaccination against Avian Influenza, please visit:
