Field production efficiency investigation of broilers immunized with a turkey herpesvirus vector vaccine expressing hemagglutinin from H9N2 subtype avian influenza virus

• Published in: Vaccine Vol. 42; no. 26; p. 126436
• Main Authors: Litao, Liu, Feng, Chen, Hongyu, Zhao, Wenbin, Chen, Fanlei, Meng, Dandan, Zhang, Xun, Jing, Xinyu, Li, Qiaomei, Liang, Honglei, Sun, Yipeng, Sun, Juan, Pu, Jinhua, Liu
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 02.12.2024; Elsevier Limited
• Subjects: Adjuvants; Allergy and Immunology; Animals; Antibodies; Antibodies, Viral - blood; Antibodies, Viral - immunology; Avian flu; Birds; Block virus infection and transmission; Chickens - immunology; Efficiency; Feed conversion; Field trial; Genetic Vectors; Hemagglutinin Glycoproteins, Influenza Virus - immunology; Hemagglutinins; Herpes viruses; Herpesvirus 1, Meleagrid - immunology; Houses; HVT-H9; Immunization; Infections; Influenza A virus; Influenza A Virus, H9N2 Subtype - immunology; Influenza in Birds - immunology; Influenza in Birds - prevention & control; Influenza Vaccines - administration & dosage; Influenza Vaccines - immunology; Maternal antibodies interference; Meleagrid alphaherpesvirus 1; Mortality; Poultry; Poultry Diseases - immunology; Poultry Diseases - prevention & control; Poultry Diseases - virology; Production efficiency; Statistical analysis; Turkey herpesvirus vector vaccine; vaccination; Vaccination - methods; Vaccines; vector vaccines; China; Production efficiency; Field trial; Block virus infection and transmission; Maternal antibodies interference; Turkey herpesvirus vector vaccine; HVT-H9
• DOI: 10.1016/j.vaccine.2024.126436
• ISSN: 0264-410X; 1873-2518

Turkey herpesvirus (HVT) vector vaccine expressing hemagglutinin from the H9N2 AIV, namely HVT-H9, were demonstrated to block H9N2 AIV infection and transmission in chickens. In this study, we evaluated the protection efficiency and production performance of broilers in HVT-H9 field trials in the presence or absence of the H9N2 AIV natural infection. HI titers against H9N2 AIV in broilers harboring maternal antibodies were successfully induced by HVT-H9. In the presence of H9N2 AIV natural infection, immunization with HVT-H9 blocked H9N2 AIV infection and reduced the mortality rate. Importantly, HVT-H9 vaccination slightly increased broiler weight and decreased the feed conversion rate in the absence of the H9N2 AIV natural infection but significantly reduced mortality rates and increased production efficiency during the H9N2 AIV natural infection. In summary, HVT-H9 immunization might block H9N2 AIV infection and improve production efficiency in the field, especially in the presence of H9N2 AIV natural infection. •Immunization with HVT-H9 improved broiler production efficiency especially in the present of the H9N2 epidemic.•HI titers against H9N2 AIV were induced by HVT-H9 in broilers harboring maternal antibodies.•Further confirmations that immunization with HVT-H9 might block H9N2 virus infection and reduces the mortality rate.•It is proposed that cellular immunity induced by HVT-H9 might be the key to preventing and controlling H9N2 infection.