Comprehensive Evaluation on Immune Efficacy of Trivalent Inactivated Avian Influenza Vaccines in Guangdong Province From 2021 to 2022
The aim of this study was to assess the quality of trivalent inactivated avian influenza vaccines of mandatory immunization purchased by government in Guangdong province,and which can provide scientific guidance for farmers regarding vaccine usage and promote the healthy development of animal epidemic prevention efforts.The avian influenza vaccines of 10 companies were evaluated from three aspects from 2021 to 2022:dynamic monitoring,immune effect evaluation,field tracking and monitoring.The mean HI antibody titers of 38 batches of avian influenza vaccines sampled in 2021 ranged from 7.40log2 to 9.61log2.For the 40 batches sampled in 2022,the mean HI antibody titers ranged from 6.22log2 to 8.98log2.The mean HI antibody titer of the new vaccine in 2022 was approximately lower by a magnitude of about 1.00log2 compared to that in 2021 following an update on avian influenza vaccine seed viruses.However,the mean HI antibody titer can increase by a range of 1.50log2 to 3.00log2 after secondary vaccination and remain elevated over an extended period whether it is SPF chickens or poultry.Despite variations in the immune responses of different chicken flocks during field tracking and monitoring,the overall antibody qualification rate for all poultry flocks after secondary vaccination exceeded 87.78％.The study suggests that mandatory immunization with avian influenza vaccines has maintained robust immune efficacy in Guangdong province over the past two years.Following secondary vaccination,the vaccine elicits a significant antibody response and provides effective protection.
万方数据
维普
