Wang Hua-qing, Guo Xin, Chen Li-juan, Yang Jie, He Jing-guo, Luo Ming, He Xiong, Zhou Yu-qing, Cao Ling-sheng, Lu Yong, Yin Da-peng, Chen Yuan-sheng, Xia Wei, Liang Xiao-feng
National Immunization Program, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
Zhonghua Liu Xing Bing Xue Za Zhi. 2007 May;28(5):433-6.
To investigate the immunity level of diphtheria antibody among children living in the areas where different coverage rates of 4-vaccines stratified by results of national immunization program (NIP) reviewed in 2004.
According to data from 4-vaccine coverage rates of NIP reviewed in 2004, 3 levels could be set. We randomly selected 2 counties at each level and then 10 villages from each county with 42 children involved who were born between 1992 and 2003. ELISA quantitative method was used to test IgG of diphtheria antitoxin.
(1) The positive rate of diphtheria antitoxin was only 49.6% with the highest as 78.1% and lowest as 33.0%. There was a significant decreasing trend of this positive rate with the increase of age. The highest (61.2%) fell in the group that were born in 2003 and the lowest (37.6%) was seen among children born in 1992 to 1995. (2) Geometric mean concentrations (GMCs) was only 0.48 IU/ml with a trend of decrease when age was increasing. There was no GMCs peak seen in children who were at the age of boosting, as expected. (3) Positive rates of children born between 2001 and 2003 were lower than 62% while the diphtheria-pertussis-tetanus (DPT) vaccine coverage rates were all higher than 90%. (4) There was no significant difference of diphtheria antitoxin positive rates between children with eligible routine immunization (58.1%) and those were ineligible (59.6%).
Other than some specific ones, children from most of the investigated counties had a low level of antibody against diphtheria. The coverage rate of DPT vaccine did not necessarily reflect the immunity against diphtheria, suggesting the increase of immunity against diphtheria an urgent task to be taken care of.
调查2004年国家免疫规划（NIP）审评结果分层的4种疫苗不同接种率地区儿童白喉抗体免疫水平。
根据2004年NIP的4种疫苗接种率数据设定3个水平。在每个水平随机抽取2个县，再从每个县随机抽取10个村，纳入42名1992年至2003年出生的儿童。采用ELISA定量法检测白喉抗毒素IgG。
（1）白喉抗毒素阳性率仅为49.6%，最高为78.1%，最低为33.0%。该阳性率随年龄增长呈显著下降趋势。最高值（61.2%）出现在2003年出生的儿童组，最低值（37.6%）出现在1992年至1995年出生的儿童中。（2）几何平均浓度（GMCs）仅为0.48 IU/ml，且随年龄增长呈下降趋势。未观察到预期的加强免疫年龄儿童的GMCs峰值。（3）2001年至2003年出生儿童的阳性率低于62%，而百白破（DPT）疫苗接种率均高于90%。（4）常规免疫合格儿童（58.1%）和不合格儿童（59.6%）的白喉抗毒素阳性率无显著差异。
除部分特定地区外，大多数被调查县的儿童白喉抗体水平较低。DPT疫苗接种率不一定反映对白喉的免疫力，提示提高对白喉的免疫力是一项亟待解决的任务。
