title: [Study on the immunity of diphtheria in children at county level with different 4-vaccine coverage rates based on the results from "National Immunization Program Review" in 2004].
abstract: OBJECTIVE
  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.
  
  
  METHODS
  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.
  
  
  RESULTS
  (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%).
  
  
  CONCLUSIONS
  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.
authors: National Immunization Program, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
authors: Hua-qing
authors: HQ
authors: Wang
authors: Xin
authors: X
authors: Guo
authors: Li-juan
authors: LJ
authors: Chen
authors: Jie
authors: J
authors: Yang
authors: Jing-guo
authors: JG
authors: He
authors: Ming
authors: M
authors: Luo
authors: Xiong
authors: X
authors: He
authors: Yu-qing
authors: YQ
authors: Zhou
authors: Ling-sheng
authors: LS
authors: Cao
authors: Yong
authors: Y
authors: Lu
authors: Da-peng
authors: DP
authors: Yin
authors: Yuan-sheng
authors: YS
authors: Chen
authors: Wei
authors: W
authors: Xia
authors: Xiao-feng
authors: XF
authors: Liang
mesh_terms: D000293:Adolescent; D017677:Age Distribution; D000907:Antibodies, Bacterial / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D002681:China; D004165:Diphtheria / Q000276:immunology* / Q000517:prevention & control*; D004166:Diphtheria Antitoxin / Q000276:immunology*; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000276:immunology*; D005260:Female; D006801:Humans; D008297:Male
chemical_list: D000907:Antibodies, Bacterial; D004166:Diphtheria Antitoxin; D015721:Diphtheria-Tetanus-Pertussis Vaccine