title: Phase I study of the immunogenicity and safety of conjugated Hemophilus influenzae type b vaccines in the elderly.
abstract: In infants, vaccines consisting of a carrier protein conjugated to the bacterial capsular polysaccharide (PRP) are far more protective against Hemophilus influenzae type b (Hib) disease than unconjugated PRP. To determine the tolerability and immunogenicity of Hib conjugate vaccines in the elderly, we vaccinated 30 volunteers, aged 69-84 years, with either PRP conjugated to an outer membrane protein complex (PRP-OMP), or PRP oligomers conjugated to CRM197, a nontoxic, mutant diphtheria toxin (HbOC). Prior to vaccination, 40% of subjects had serum anti-PRP antibody levels < 1.0 microgram ml-1. Four weeks following vaccination, all subjects had concentrations > 1.0 microgram ml-1, a level generally considered to be protective. The post-vaccination geometric mean concentrations were 35.5 and 50.1 micrograms ml-1 for the PRP-OMP and HbOC groups, respectively (0.05 < P < 0.10). Subjects in the HbOC group, but not the PRP-OMP group, showed, on average, ten fold increases in IgG antibody to diphtheria toxoid after conjugate vaccination. Side-effects of vaccination were mild except in one subject given HbOC, who developed extensive erythema and swelling of the injected arm.
authors.affiliation: Department of Medicine, Mount Zion Hospital, University of California, San Francisco, USA.
authors.forename: E
authors.initials: E
authors.lastname: Kantor
authors.forename: J S
authors.initials: JS
authors.lastname: Luxenberg
authors.forename: A H
authors.initials: AH
authors.lastname: Lucas
authors.forename: D M
authors.initials: DM
authors.lastname: Granoff
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000276:immunology*; D001425:Bacterial Outer Membrane Proteins / Q000276:immunology; D004167:Diphtheria Toxin / Q000276:immunology; D005260:Female; D018073:Haemophilus Vaccines / Q000009:adverse effects* / Q000276:immunology*; D006801:Humans; D008297:Male; D009345:Neisseria meningitidis / Q000276:immunology; D018074:Vaccines, Conjugate / Q000009:adverse effects / Q000276:immunology
chemical_list: D001425:Bacterial Outer Membrane Proteins; D004167:Diphtheria Toxin; D018073:Haemophilus Vaccines; D018074:Vaccines, Conjugate