水痘减毒活疫苗两针法免疫效果及安全性评价

摘要:目的　研究儿童接种水痘减毒活疫苗（Varicella Attenuated Live Vaccine，VarV）初免后不同时间抗体变化规律及不同间隔两针法免疫的安全性和有效性。方法　用随机整群抽样法，抽取深圳市罗湖辖区2～7岁接种过1剂水痘减毒活疫苗儿童702名。结果　不良反应总发生率2.57%，3组间出现不良症状人数差异无统计学意义（χ2＝3.327，P＝0.204）；接种第1剂（初免）后1年与3年和5年接种组抗体水平的差异有统计学意义（χ2＝22.7，P＝0.004），初免后1年接种组抗体阳转率（χ2＝4.4，P＝0.113）与其余2组相比无统计学差异；接种第2剂（再次）免疫后3组抗体水平比较差异有统计学意义（χ2＝75.8，P＜0.001）；从抗体水平差值均数上看，初免后3年与5年接种组均比初免后1年抗体水平升高较大（P值分别为0.001和0.000），但初免后3年与5年接种组抗体水平升高差值均数差异无统计学意义（P＝0.392）；初免与再次免疫抗体水平中位数比较，初免后1年与3年和5年接种组抗体变化具有统计学差异（P＜0.001），而初免后3年和5年接种组抗体变化并无统计学差异。结论　接种第1剂水痘减毒活疫苗后抗体滴度随着时间增加而降低，两针法有助于提高儿童抗体水平，有良好的免疫效果和安全性。

Immune effect and safety evaluation on the two-dose schedule for Live Attenuated Varicella Vaccine

Abstract: Objective The study aimed to investigate the dynamic change in the level of Varicella antibody after different vaccination intervals, and to evaluate the vaccine safety and efficiency of the two-dose vaccination schedule of Attenuated Live Varicella Vaccine (VarV) in children. Methods Random clustering method was used to select 702 children aged 2 to 7 years from Luohu District of Shenzhen City. Those children vaccinated as least one dose of VarV were categorized into three groups by vaccination intervals (i.e. 1 year, 3 years and 5 years). At the end of follow-up, data were collected from 213 children in the 1-year group, 237 children in the 3-year group and 209 children in the 5-year group. Results Side effect events occurred to 2.57% of the total enrolled children, and no statistical significance observed (χ2=3.327, P=0.204). The antibody levels of three groups were significantly different (χ2=22.7, P=0.004), no statistically significant difference was observed in the seroconversion rate of the three groups (χ2=4.4, P=0.113). The seropositive rate decreased annually. After the second dose, the antibody levels were significantly different among three intervention groups (χ2=75.8, P<0.001). The increase in antibody titers of the 3-year interval group and the 5-year interval group was significant higher than that of the 1-year group (P=0.001 and 0.000, receptively), but the increase of the 3-year group and the 5-year group were the same (P=0.392). The increase and the median of antibody titers were different between the 3-year group and the 1-year group, and between the 5-year group and the 1 year group (P<0.001). We did not detect any difference in the antibody level between the 3-year group and the 5-year group. Conclusion The antibody titers decreased after the first dose of vaccine. Two doses of vaccine can improve the safety and efficiency of Varicella vaccine.