title: [The investigation of natural antibody level to Haemophilus influenzae type b polysaccharide in China].
abstract: OBJECTIVE
  Investigation of natural antibody level to Haemophilus influenzae type b polysaccharide in China.
  
  
  METHODS
  1,596 sera samples from cord (55 sera), infants (1,383 sera), children (66 sera), adult (52 sera) and elderly (40 sera) were collected from different provinces and the natural antibody level to PRP was measured with a standardized radio immunoassay 125I-labeled PRP.
  
  
  RESULTS
  Antibody level of infants under 5 year olds in different provinces was different. Levels of infants from Gansu, Guizhou, Jiangxi province were lower (< or = 0.07 microgram/ml) than from Shanhai, Guangxi and Heilognjiang. Comparison of antibody levels with different age groups showed that infants aged 6 months to 5 years having the lowest antibody level (< 0.15 microgram/ml). The level increased rapidly during 6-10 years of age (> or = 1.0 microgram/ml). The levels of adults and elderly were about 1-1.5 micrograms/ml.
  
  
  CONCLUSIONS
  General immunity against Hib disease were low in Chinese population. Children aged 6 months to 5 years old with lowest natural antibody level to PRP were the population under high risk.
authors.affiliation: National Institute for the Control of Pharmaceutical & Biological Products, Beijing.
authors.forename: Z
authors.initials: Z
authors.lastname: Yuan
authors.forename: F
authors.initials: F
authors.lastname: Li
authors.forename: Y
authors.initials: Y
authors.lastname: Li
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000907:Antibodies, Bacterial / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D005260:Female; D019741:Haemophilus influenzae type b / Q000276:immunology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D011863:Radioimmunoassay
chemical_list: D000907:Antibodies, Bacterial; D011135:Polysaccharides, Bacterial