Abstract Title
Development of avian influenza (H5+H7) trivalent DNA vaccine
Abstract
DNA vaccine is easy to develop as multivalent vaccine. Several subtypes of HPAIVs pose threat to poultry, and a trivalent inactivated vaccine has been used in China since 2022. This study aims to develop a multivalent DNA vaccine against the H5 and H7 subtypes of HPAIVs.
We constructed plasmids pH5-FJ(H5-Re13), pH5-SX(H5-Re14), and pH7-YN(H7-Re4) with chicken-codon-optimized HA genes from DK/FJ/S1424/20(H5N6), SW/SX/4-1/20(H5N8), and CK/YN/SD024/21 (H7N9), respectively. The HA expression in 293T cells was validated by IFA and Western blot assays. We then prepared the trivalent DNA vaccine by mixing 30 μg of each plasmid. The vaccine was used to immunize 3-week-old SPF chickens intramuscularly at a dose of 90 μg. The booster was given at the same dose three weeks after the primary immunization. The chickens were challenged intranasally with different viruses at a dose of 106 EID50 one week after the booster. The immune responses were monitored by assessing HI antibody levels and protection efficacy.
In transfected cells, HA proteins were highly expressed. Specific antibodies were detectable two weeks after vaccination and increased after the booster. When challenged with the lethal dose of viruses, all the vaccinated chickens were completely protected, meaning no clinical signs, no deaths, and no virus shedding, whereas the control birds all died very quickly.
These findings indicate that the trivalent DNA vaccine is highly effective in preventing the currently epidemic clade 2.3.4.4h and 2.3.4.4b H5, and H7 viruses in China.
We constructed plasmids pH5-FJ(H5-Re13), pH5-SX(H5-Re14), and pH7-YN(H7-Re4) with chicken-codon-optimized HA genes from DK/FJ/S1424/20(H5N6), SW/SX/4-1/20(H5N8), and CK/YN/SD024/21 (H7N9), respectively. The HA expression in 293T cells was validated by IFA and Western blot assays. We then prepared the trivalent DNA vaccine by mixing 30 μg of each plasmid. The vaccine was used to immunize 3-week-old SPF chickens intramuscularly at a dose of 90 μg. The booster was given at the same dose three weeks after the primary immunization. The chickens were challenged intranasally with different viruses at a dose of 106 EID50 one week after the booster. The immune responses were monitored by assessing HI antibody levels and protection efficacy.
In transfected cells, HA proteins were highly expressed. Specific antibodies were detectable two weeks after vaccination and increased after the booster. When challenged with the lethal dose of viruses, all the vaccinated chickens were completely protected, meaning no clinical signs, no deaths, and no virus shedding, whereas the control birds all died very quickly.
These findings indicate that the trivalent DNA vaccine is highly effective in preventing the currently epidemic clade 2.3.4.4h and 2.3.4.4b H5, and H7 viruses in China.
Co-Author(s)
Jiongjie Li, Wenyu Liu, Jiaxin Yang, Pucheng Chen, Jinxiong Liu, Xianying Zeng, Guohua Deng, Yanbing Li, Yongping Jiang*, Hualan Chen*
(State Key Laboratory for Animal Disease Control and Prevention, Harbin Veterinary Research Institute, CAAS, Harbin 150069, China)
Abstract Category
Diagnostics, vaccination, or other mitigation strategies for poultry and wildlife