Immunogenicity Evaluation Of An Inactivated H₅N₁ Subtype Avian Influenza Vaccine On Duck

HPAI is one of the most serious infectious diseases that threat the poultry industry and human public sanitation. ATV H5N1 subtype inactivated vaccine has proved to have satisfied immunogenicity to chicks. However, no available data of vaccine could be found for the application on ducks.The AIV H5N1 subtype inactivated vaccine from Harbin Veterinary Research Institute were applied to evaluate the systematic immunogenicity to raised ducks. From February in 2004 to June in 2005, the dynamic of maternal antibody was taken on to 6000 ducks from 7 groups in Shanghai Qingpu region through HI antibody detection, and its immunogenicity to different duck species. The results showed that the vaccine had good immunogenicity.The dynastic indicated that the maternal antibody level and its maintenance time of 1500 meat ducklings from three groups paralleled to that of their parents.To 3000 one-day age ducklings from three groups, including meat duck, breed duck and egg duck, antibody detections indicated that maternal antibody of meat duck was lower than that of breed and egg ducks, and its maintenance time was still shorter than breed and egg ducks. The difference of maternal antibody and maintenance time between breed duck and egg duck was unremarkable.H5N1 subtype inactivated vaccine was applied to all groups. To one group 1500 meat ducklings, the difference of HI antibody level through neck hypodermic injection between 0.3ml and 0.5ml dosages was extremely remarkable, and 0.5ml immunity dosage could induce fairly satisfied effects. When ducklings' maternal antibody maintained high level HI antibody couldn't reach the protective level after immune 0.5ml vaccine for 2 weeks. When maternal antibody fairly disappeared HI antibody was produced slowly after immunity and could not reach the protective level all along.To one group 1000 breed ducklings, the difference of HI antibody level between 0.3ml and 0.5ml dosages in first immunity through neck hypodermic injection was not remarkable, but the difference of protective antibody maintenance time was remarkable. The protective antibody induced at 0.5ml dosage in one time immunity could prolong 3 weeks than at 0.3ml, and ducks at 0.5ml dosage had no obvious harmful reactions.To one group 1500 breed ducklings, differences of HI antibody level among 0.3ml, 0.5ml and 1.0ml dosages in first immunity through neck hypodermic injection were extremely remarkable. The protective antibody level of first time immunity induced at 0.3ml vaccine could only maintain 4 weeks; at 0.5ml could maintain 10 weeks; at 1.0ml could maintain 11 weeks, but ducks appeared fairly great harmful reactions.To breed duck and egg ducks, the differences of HI antibody level and maintenance time through muscle injection with different dosages were not remarkable in second and third immunities.