接种2剂次水痘疫苗的突破病例前瞻性观察及抗体动态变化分析

Prospective observation of breakthrough cases and analysis of antibody dynamic changes after two doses of varicella

目的分析天津市儿童接种2剂次水痘疫苗后的突破率及抗体水平变化情况,并与仅接种1剂次的儿童进行比较。方法选取1112名接种2剂次水痘疫苗的儿童作为试验组,按照同一街乡选择年龄相差1岁之内仅接种过1剂次,且1剂次接种时间与试验组第1剂次接种时间相差小于1个月的儿童作为对照组,对两组儿童水痘发病情况进行3年的观察。各选取两组中108名儿童同时在第1~3年采集血清进行抗体检测,采用χ^(2)检验、t检验、方差分析等比较两组突破率以及组间和组内3年间的抗体水平和抗体阳性率。结果试验组累计突破率0.54%(6/1112),低于对照组的3.96%(44/1112,χ^(2)=29.544,P<0.001),试验组接种水痘疫苗后水痘抗体GMC水平逐年降低(F=18.291,P<0.001),对照组的GMC水平也逐年降低(F=91.383,P<0.001)。各检测年度试验组和对照组的GMC水平差异有统计学意义(P<0.001)。接种2剂次疫苗的试验组3年间的抗体阳性率差异有统计学意义(χ^(2)=11.107,P<0.01),接种第1年与第3年的阳性率差异有统计学意义(P<0.01),对照组3年间的阳性率差异无统计学意义(χ^(2)=3.351,P>0.05)。各检测年度试验组阳性率均高于对照组(P<0.001)。结论接种2剂次疫苗能够显著提升接种后的抗体水平和抗体阳性率,但随着时间的延长仍呈下降趋势,应根据实际情况考虑实行再次加强免疫。

Objective To investigate the breakthrough rate and antibody level of children vaccinated two doses varicella vaccine in Tianjin city,and to compare them with those vaccinated one dose.Methods A total of 1112 children who were vaccinated two doses varicella vaccine were selected as the experimental group.According to the same street and township,children who had received only one dose within one year of age difference,and whose first injection time was less than one month from the first dose of varicella vaccine in the experimental group were selected as the control group.A three-year prospective observation was conducted on the incidence of varicella in the two groups.108 pairs of children in the two groups were selected to collect antivaricella serum in the first to third year.The rate of breakthrough cases,antibody level and antibody positive rate were compared byχ^(2) test,t-test and variance analysis between and within the two groups in three years.Results The cumulative breakthrough rate of the experimental group was 0.54%(6/1112),which was lower than that of the control group 3.96%(44/1112,χ^(2)=29.544,P<0.001).The GMC level of antibody in the experimental group decreased year by year(F=18.291,P<0.001),and the GMC level in the control group also decreased year by year(F=91.383,P<0.001).There was significant difference in GMC level between the two groups(P<0.001).The difference of antibody positive rate in the experimental group was statistically significant in three years(χ^(2)=11.107,P<0.01),there was significant difference in the positive rate between the first year and third year(P<0.01),there was no significant difference in the positive rate of the control group in three years(χ^(2)=3.351,P>0.05).The positive rate of the experimental group was higher than that of the control group(P<0.001).Conclusion Two doses varicella vaccine can significantly improve the antibody level and positive rate,but it still shows a downward trend with the extension of time.It is necessary to consider strengthening immunization according to the actual situation.