Immunologic priming by one dose of Haemophilus influenzae type b conjugate vaccine in infancy

J Infect Dis. 1995 Nov;172(5):1268-72. doi: 10.1093/infdis/172.5.1268.


Immunogenicity of one dose of Haemophilus influenzae type b (Hib) conjugate vaccine in infancy and its ability to induce immunologic memory was studied in infants immunized at 4 and 14 months with either PRP-OMP (Hib polysaccharide conjugated with Neisseria meningitidis group B outer membrane protein complex) or PRP-T (Hib polysaccharide-tetanus toxoid conjugate) and compared with three doses of the same vaccines at 4, 6, and 14 months. Each group received diphtheriatetanus-pertusis vaccine at 3, 4, and 5 months of age. At 7 months of age, both vaccines were immunogenic after one dose, even though higher antibody concentrations were achieved after two doses. A booster dose given at 14 months resulted in a high antibody concentration and a strongly IgG-dominated isotype distribution, speaking for a secondary-type response in all groups, including those who had received only one dose in infancy. Subsequent persistence of antibodies suggestive of full protection for up to 36 months was similar in all groups.

Publication types

  • Clinical Trial
  • Comparative Study
  • Controlled Clinical Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Aging / immunology
  • Antibodies, Bacterial / blood
  • Bacterial Outer Membrane Proteins / immunology*
  • Haemophilus Vaccines / immunology*
  • Haemophilus influenzae / immunology*
  • Humans
  • Immunoglobulin G / blood
  • Immunoglobulin M / blood
  • Immunologic Memory*
  • Infant
  • Neisseria meningitidis / immunology
  • Polysaccharides, Bacterial / immunology*
  • Tetanus Toxoid / immunology*
  • Vaccines, Conjugate / immunology*


  • Antibodies, Bacterial
  • Bacterial Outer Membrane Proteins
  • Haemophilus Vaccines
  • Haemophilus influenza type b polysaccharide vaccine-tetanus toxin conjugate
  • Haemophilus influenzae-type b polysaccharide-Neisseria meningitidis outer membrane protein conjugate vaccine
  • Immunoglobulin G
  • Immunoglobulin M
  • Polysaccharides, Bacterial
  • Tetanus Toxoid
  • Vaccines, Conjugate