乙型肝炎疫苗加强免疫效果评价

Evaluation on Efficacy of Boosting Dose of Hepatitis B Vaccine

宁波市江北区和镇海区自 1994年起对满 5周岁儿童普遍进行乙型肝炎 (乙肝 )疫苗加强免疫 (1针 ) ,加强免疫接种率 >90 % ,至今已实行了 6年。为评价乙肝疫苗加强免疫的效果 ,在上述两个区和未实行加强免疫的宁海县 ,采用整群随机抽样法抽取 1989～ 1998年出生的儿童 90 1人和 398人 ,采血检测乙肝病毒表面抗原 (HBsAg)和抗体 (抗 -HBs)、乙肝病毒核心抗体 (抗 -HBc) ,观察两组儿童阳性率和抗体滴度的差别。结果显示 :加强免疫组 5～ 6岁儿童抗 -HBs的阳性率 (89 90 %和 83 33% )显著高于未加强免疫组的同龄儿童 (6 5 2 2 %和 6 1 2 2 % ) ,但随着年龄增长阳性率趋于接近 ,10岁组前者抗 -HBs阳性率为 6 7 0 1% ,后者 5 3 38%。加强免疫 2年抗 -HBs几何平均滴度 (GMT)达 71 79%mIU/ml,至 6年时降为 45 0 0mIU/ml,未加强免疫组儿童的抗 -HBs是持续下降 ,初免10年时其滴度为 2 6 97mIU/ml。加强免疫组和未加强免疫组儿童的HBsAg和抗 -HBc阳性率无明显差异。由此可见 ,对 5周岁儿童实施加强免疫可使抗 -HBs总体水平短期内明显升高 ,持续时间有所延长 ,但对儿童乙肝病毒感染无明显影响。因此认为 ,在儿童乙肝疫苗基础免疫后 10年内无需普遍实施加强免疫 ,5岁加强免疫在时机上不完全合理。

Since 1994,in Jiangbei and Zhenghai districts of Ningbo City,one boosting dose of hepatitis B(HB) vaccine had been generally given to 5-year-old children for 6 years.For evaluating the efficacy of boosting of HB vaccine,using random cluster-sampling method,we selected 901 children born in 1989-1998 in the above mentioned two districts and 398 children unboosted in Ninghai county as well.Blood samples were collected for HBsAg,anti-HBs and anti-HBc detection.The results showed that the anti-HBs positive rate in 5-6 year old children (1-2 years ofter boosting) was much more higher(89.90% and 83.33%) than that in unboosted children of the same age (65.22% and 61.22%).But along with the age growing,the anti-HBs positive rate declined continuously,at the age of 10,anti-HBs positive rate in the former was 67.01%,in the latter was 53.38%.The GMT of anti-HBs was 71.79mIU/ml 2 years after boosting,it decreased to 45.00mIU/ml after 6 years.In unboosted children,it continuously declined to a level of 26.97 mIU/ml at the tenth year of basic immunization.Positive rate of HBsAg and anti-HBc had no significant difference between boosted and unboosted children.It is thus clear,the boosting dose of HB vaccine to 5-year-old children though could raise anti-HBs at a total level in a short time and sustained but it had no preventive effect on hepatitis B virus infection.So,we hold that within 10 years of basic HB immunization,it is not necessary to give boosting dose,since that is not a suitable way of doing.