Reduction of oropharyngeal carriage of Haemophilus influenzae type b (Hib) in children immunized with an Hib conjugate vaccine

J Infect Dis. 1991 Nov;164(5):982-6. doi: 10.1093/infdis/164.5.982.


The oropharyngeal carriage of Haemophilus influenzae type b (Hib) was studied among 725 healthy 3-year-old children who had or had not been immunized with an Hib conjugate vaccine. Oropharyngeal swabs were collected during the childrens' well-child visit to their local child health center. Fourteen (3.5%) of the 398 unvaccinated children were oropharyngeal carriers of Hib, whereas none of the 327 children who had received Hib conjugate vaccine carried Hib (P less than .001). Carriage rates of non-type b H. influenzae (19%) or Streptococcus pneumoniae (18%) were the same irrespective of the Hib vaccination status of the children. Thus Hib conjugate vaccine, unlike Hib polysaccharide vaccine, seems to be able to prevent oropharyngeal colonization by Hib.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Vaccines / immunology*
  • Carrier State / immunology*
  • Carrier State / microbiology
  • Child, Preschool
  • Diphtheria Toxoid / immunology*
  • Haemophilus Infections / immunology*
  • Haemophilus Infections / microbiology
  • Haemophilus Vaccines*
  • Haemophilus influenzae / immunology*
  • Haemophilus influenzae / isolation & purification
  • Humans
  • Oropharynx / microbiology*
  • Vaccination


  • Bacterial Vaccines
  • Diphtheria Toxoid
  • Haemophilus Vaccines
  • Haemophilus influenzae type b-polysaccharide vaccine-diphtheria toxoid conjugate