水痘疫苗初免与加强免疫后抗体水平调查

The dynamic change of antibody level against varicella in children immunized with first dose and booster dose vaccine

目的观察水痘疫苗初免后免疫持久性及加强免疫后免疫效果,为水痘疫情的控制提供参考依据。方法对初免1～6年后的儿童300名进行抗体水平测定,并进行不同接种年限的比较;随机抽取约一半对象进行加强免疫,一年后与未进行加强免疫的对象进行抗体水平比较。阳性率比较用χ2检验,平均浓度比较用t检验或方差分析。α定为0.05。结果初免后抗体阳性率为70%;随接种年限的延长,抗体水平逐渐降低(F=4.529,P=0.012);加免后阳性率明显增高,与初免之间的差异有统计学意义(χ2=5.784,P=0.016;χ2=7.760,P=0.005;χ2=10.859,P=0.001)。结论水痘疫苗初免后儿童获得一定的免疫保护;疫苗保护效果随接种年限的延长逐渐减弱;二次免疫在一定程度上可能减少或防止突破性病例发生。

Objective To observe long term effect of varicella first dose vaccination and the immune effect of booster dose immunization in children. Methods A total of 300 children immunized with first dose varicella vaccine for 1-6 years were selected and tested for antibody level. 172 participants were randomly selected and given a booster dose vaccine and antibody level was measured a year later. Chi-square test, T-test and AVOVA were used for data analysis. Results The positive rate of antibody in children with first dose varicella vaccine was 70% and the level decreased annually （F=4. 529, P=0. 012） . With the booster dose vaccination, the positive rate of antibody increased greatly, the differences of positive rates between first and booster dose in three age groups were significant （Χ^2=5.784, P=0.016;Χ^2=7.760, P=0.005; Χ^2 =10.859, P= 0. 001）. Conclusions Although the immunization of single dose varicella vaccine is able to provide children a certain degree of protection, but the antibody level drops each year, Therefore, a booster dose is strongly recommended in order to prevent the outbreaks of varicella.