2013～2015年湖北省规模化蛋鸡场H9N2亚型禽流感疫苗免疫效果调查

EFFICACY OF H9N2 AVIAN INFLUENZA VIRUS VACCINE IN LARGE-SCALE LAYER FARMS IN HUBEI PROVINCE FROM 2013 TO 2015

禽流感(avian influenza,AI)是由A型流感病毒(Influenza A Virus,IAV)感染禽类引起的一种高度接触性传染病,临床表现为从呼吸系统到全身严重败血症等多种症状。为了解近年来湖北省H9N2亚型禽流感疫苗的免疫效果,2013年6月到2015年12月从湖北省规模化蛋鸡场随机采取样本共6648份,用血凝抑制实验(hemagglutination inhibition,HI)测定了H9N2亚型禽流感抗体滴度。对不同月份样本进行分析显示,2013年8月平均抗体滴度最低为8.7 log2,10月的平均抗体滴度最高为9.44log2,但依然小于2014和2015年的最小平均抗体滴度。2014年1月的平均抗体滴度最低(9.62 log2),5月的平均抗体滴度最高(12.34 log2),2015年的6月平均抗体滴度最低(10.24 log2),11月平均抗体滴度最高(13.03 log2);对不同日龄样本进行分析显示,蛋鸡的平均抗体滴度随着日龄的增加而增加,不同阶段的蛋鸡的抗体滴度平均值呈现递增现象,且都大于9 log2,但是在120<日龄≤200的蛋鸡中抗体滴度部分值小于4 log2,存在着离散度大,极差大的特点;3年的平均抗体滴度对比显示,2013~2015年平均抗体滴度呈现递增现象,且都大于9 log2。检测结果显示,H9N2亚型禽流感疫苗的总体免疫效果良好,能达到保护鸡群受同种毒株感染的目的,但是不同月份、不同日龄的平均抗体滴度存在差异。

Avian influenza is a highly contagious disease caused by influenza A virus and affects from the respiratory system to seriously systemic sepsis and other symptoms.In order to investigate efficacy of H9N2subtype avian influenza vaccine on larger-scale layer farms in Hubei province,6648blood samples were randomly collected from June2013to December2015.The antibody levels of H9N2subtype avian influenza vims were determined by hemagglutination inhibition(HI).The results showed that the lowest antibody titers were8.7log2in August and the highest titers9.44log2in October of2013,the lowest titers were9.62log2in January and the highest tiers12.34log2in May of2014,and the lowest titers were10.24log2in June and the highest tiers13.03log2in November of2015.The average antibody titers of the chickens at different ages showed an increasing phenomenon,reaching to more than9log2.However,some of the antibody titers were less than4log2when chickens were between120-200days old.The investigation concluded that the antibody level of H9N2subtype avian influenza vaccine was good in general on layer farms in Hubei province.However,some differences in the antibody titers of H9N2subtype avian influenza vaccine were observed in different ages and months of the years.