b型流感嗜血杆菌结合疫苗接种后5年的免疫持久性观察

Five-year immunity persistence following immunization with haemophilus influenzae type b conjugate vaccine

目的:评价国产b 型流感嗜血杆菌(Hib)结合疫苗在我国3月龄至5岁健康婴幼儿接种后5年的免疫持久性。方法:选择江苏省涟水县Ⅲ期临床试验(试验疫苗组)中完成全程免疫接种者作为研究对象,2019年11-12月开展接种后5年的采血工作,并采用ELISA法检测血清抗b 型流感嗜血杆菌-荚膜多糖(Hib-PRP)抗体,计算血清抗Hib-PRP抗体长期保护率和短期保护率、几何平均浓度(GMC)和几何平均浓度增长倍数(GMFI)。结果:共纳入研究对象580例,其中3~5月龄组、6~11月龄组以及1~5岁组分别有158、207和215例,各年龄组接种后5年的血清抗PRP抗体的短期保护率(≥0.15 μg/ml)和长期保护率(≥1.0 μg/ml)均分别为89.24%、90.34%和98.60%,GMC分别为3.95、3.11和10.01 μg/ml,GMFI分别为29.04、11.01和3.26。结论:在3月龄至5岁的婴幼儿中Hib结合疫苗接种后5年仍具有良好的免疫持久性。

Objective To evaluate the immunity persistence five years later after immunization with Haemophilus influenzae type b(Hib)conjugate vaccine in healthy infants/children aged 3 months to 5 years in China.Methods The children were subjects who completed the whole-schedule immunization in the phaseⅢclinical trial in Lianshui county of Jiangsu povince was selected for the collection of blood samples at 5 years after vaccination from November to December,2019.The enzyme-linked immunosorbent assay(ELISA)was used to detect Hib polyribosyl-ribitol-phosphate antibody(anti-Hib-PRP),and the long-term/short-term protection rate,geometric mean concentration(GMC)and geometric mean concentration increase fold(GMFI)of serum anti-Hib-PRP were calculated.Results A total of 580 children were enrolled in this study,of which 158,207 and 215 belonged to 3-5 month age group,6-11 month age group and 1-5 year age group,respectively.The short-term(≥0.15μg/ml)/long-term(≥1.0μg/ml)protection rates of serum anti-PRP in the three groups after immunization were 89.24%,90.34%and 98.60%,respectively;the GMC were 3.95μg/ml,3.11μg/ml and 10.01μg/ml respectively,and the GMFI were 29.04,11.01 and 3.26 respectively.Conclusions Hib conjugate vaccine can still have good immunogenicity after 5 years of primary immunization in healthy infants/children aged 3 months to 5 years in China.