深圳市学龄前儿童不同免疫接种方式对白喉抗体水平的影响

  目的  评价深圳市学龄前儿童白喉免疫状况及影响因素，为有效监测学龄前儿童白喉IgG抗体水平提供参考。  方法  采用随机抽样的方法，采集深圳市296名4~6岁学龄前儿童血清样本，使用酶联免疫吸附试验测定血清中白喉抗体滴度，分析疫苗种类、接种时间等不同免疫状态对白喉IgG抗体几何平均浓度(GMC)、抗体阳性率的影响。  结果  深圳市学龄前儿童的白喉IgG抗体GMC为0.71 IU/mL，阳转率为33.1%；不同年龄儿童白喉抗体GMC、抗体阳转率差异均有统计学意义(F/χ2值分别为11.77，27.45，P值均 < 0.01)；不同免疫完成度、疫苗种类、末剂接种时间间隔儿童白喉抗体GMC差异均有统计学意义(F值分别为49.53，12.95，11.61，P值均 < 0.01)；不同免疫完成度、疫苗种类、末剂接种时间间隔儿童白喉抗体阳转率差异均有统计学意义(Fisher确切概率法，P值均 < 0.01)。  结论  深圳市学龄前儿童总体白喉抗体阳转率较高，及时完成白喉疫苗的全程免疫或接种多联疫苗可提高抗体水平，对学龄前儿童能起到较好的保护作用。

Effect of different immunization schedules on diphtheria antibody level among preschool children in Shenzhen

  Objective  To evaluate the immunity and influencing factors of diphtheria among preschool children in Shenzhen, to provide reference for effective monitoring of diphtheria IgG antibody level in preschool children.  Methods  Serum samples were collected from 296 preschool children aged 4-6 who were recruited in Shenzhen. The diphtheria antibody titer in serum was determined by enzyme-linked immunosorbent assay, and the effect of different immumuzation schedule including types of vaccine and vaccination timing, on the geometric mean concentration (GMC) of diphtheria IgG antibody and antibody positive rate were analyzed.  Results  The GMC of diphtheria IgG antibody was 0.71 IU/mL, and the positive conversion rate was 33.1%. There were significant differences in antibody GMC and antibody positive conversion rate of diphtheria in different age groups(F/χ2=11.77, 27.45, P < 0.01). The GMC and antibody positive conversion rate showed significant differences by diphtheria antibodies, vaccine types and end dose vaccination intervals(F=49.53, 12.95, 11.61, P < 0.01). There were statistically significant differences in the positive conversion rate of diphtheria antibodies in children with different types of diphtheria antibodies, vaccine types of diphtheria antibodies, and diphtheria antibodies at the time interval of final vaccination (Fisher exact probability method, P < 0.01).  Conclusion  The overall positive conversion rate of diphtheria antibody in preschool children in Shenzhen is high. Timely completion of full diphtheria vaccination can improve the antibody level and plays a better role in protecting preschool children.