新生儿单纯乙型肝炎血源疫苗的免疫持久性和远期保护效果

目的 掌握我国新生儿单纯接种乙型肝炎血源疫苗后的免疫持久性和远期预防效果；观察新生儿免疫较长时间后是否需加强免疫。方法 在湖南湘潭市等4个乙型肝炎疫苗试点区间，对1986－1988年出生并接种乙型肝炎血源疫苗的新生儿，连续14－15年按免疫儿年龄分层随机抽样采血随访，累计随访21680人次，观察免疫儿HBsAg、抗－HBs和抗－HBc的动态变化。结果 新生儿单纯乙型肝炎血源疫苗全程基因免疫后，在15年随访中没有加强免疫，各试点区免疫儿童HBsAg携带率低于1．66％，携带率没有随免疫后的延长而增加；阻断HBV慢性感染的效果持续在90％左右（95％可信限为：83．1％－97．2％）；免疫后不同年限间HBsAg携带率、HBV感染率和保护效果差异均无显著性（P＞0．05）。免疫儿抗－HBs阳性率随免疫后年限延长而逐年明显下降，至第9－10年下降为40％－50％，之后数年内下降幅度不大，至免疫后13－14年抗－HBs阳性率维持在30％－42％；抗－HBs滴度下降了90％。结论 新生儿单纯乙型肝炎疫苗接种后抗－HBs阳性率与滴度的下降不影响其远期预防效果；就群体而言，新生儿及时完成全程免疫后，无需加强免疫可有效阻断HBV感染后成为HBsAg慢性携带者，而很有可能终生受益。

Long-term efficacya and persistence of chinese infants after receiving only active plasma-derived hepatitis B vaccine

Objective To determine the long\|term efficacy and persistence of Chinese infants after receiving only active plasma\|derived hepatitis B vaccine,and to evaluate if providing booster vaccination after basic hepatitis B immunization is necessary.Methods Infants,who were born in 1986\|1988 in four demonstrative hepatitis B immunization trial areas of Hunan,Guangxi,Hebei and Shanghai after receiving only active plasma\|derived hepatitis B vaccination,had been randomly followed up for 15 years.HBsAg,anti\|HBs and anti\|HBc in 21 680 person\|times were tested using commercial SPRIA kits.Results Prevalence of HBV carriers was less than 1.66% among all children vaccinated with only active plasma\|derived hepatitis B vaccine in 4 clinical trial areas.Prevalence of HBsAg did not increase with years after vaccination,90%(95% Cl :83.1%\|97.2%) effectiveness of hepatitis B vaccine persisted for 15 years in preventing chronic HBV infection.Carriage,HBV infection and efficacy were not different among alloage groups ( P>0 05 ).Seroprotection rate (anti\|HBs>10 mIU/ml) and quantity of anti\|HBs were significantly decreased with years after vaccination.Seroprotection rates of anti\|HBs were 40%\|50% and 30%\|42% during the 9 th \|10 th year and the 13 th \|14 th year of vaccination,respectively.Titer of anti\|HBs declined by 90% after 14 years.Conclusion These results showed that long\|term efficacy of only active plasma\|dervied hepatitis B vaccination,which was not affected by decline in seroproteation rate and titer of anti\|HBs.For children and adults whose immune status is normal,booster doses of vaccine are not recommended.