Priming and induction of Haemophilus influenzae type b capsular antibodies in early infancy by Dpo20, an oligosaccharide-protein conjugate vaccine.
A conjugate vaccine (Dpo20) was made by direct coupling of diphtheria toxoid and oligosaccharides obtained by periodate oxidation of Haemophilus influenzae type b capsular polysaccharide. This approach gave a higher multiplicity of saccharides per protein and greater immunogenicity in infancy than our previously studied conjugates. Thirty-three healthy infants received three sequential injections, and no serious side effects were observed. When Dpo20 was given with diphtheria-tetanus-pertussis vaccine at ages 2, 4, and 6 months, the geometric mean titer of anticapsular antibody rose to 5.9 micrograms/ml at age 7 months. Dpo20 given at 3, 5, and 7 months raised the mean to 3.2 micrograms/ml at 7 months (after two injections) and 15.4 micrograms/ml at 10 months. The antibodies included IgG and were bactericidal in vitro. Thus, antibody activities potentially protective against invasive H. influenzae b infections were induced in the most susceptible age range. The infants also became primed for mature-for-age responses to (unconjugated) polysaccharide vaccine given as a booster at age 12 months.
D000367:Age Factors; D000907:Antibodies, Bacterial / Q000032:analysis*; D016667:Bacterial Capsules; D001428:Bacterial Vaccines / Q000009:adverse effects / Q000276:immunology*; D004168:Diphtheria Toxoid / Q000009:adverse effects / Q000276:immunology*; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D004338:Drug Combinations / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D018073:Haemophilus Vaccines; D006193:Haemophilus influenzae / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary; D007136:Immunoglobulins / Q000032:analysis; D007223:Infant; D010567:Pertussis Vaccine / Q000276:immunology; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D013745:Tetanus Toxoid / Q000276:immunology
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D004168:Diphtheria Toxoid; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D004338:Drug Combinations; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; C052180:Haemophilus influenzae type b-polysaccharide vaccine-diphtheria toxoid conjugate; D007136:Immunoglobulins; D010567:Pertussis Vaccine; D011135:Polysaccharides, Bacterial; D013745:Tetanus Toxoid