title: Serum antibody responses of weanling mice and two-year-old children to pneumococcal-type 6A-protein conjugate vaccines of differing saccharide chain lengths.
abstract: Type 6A pneumococcal polysaccharide (PS) fractions having mean lengths 2, 7, or 14 repeat units were coupled to tetanus toxoid, giving conjugates T-6A-2, T-6A-7 or T-6A-14. In weanling outbred mice, type-6A serum antibody responses were minimal to T-6A-7 but significantly higher to T-6A-2 and T-6A-14. In contrast, two-year-old humans responded increasingly to T-6A-2, T-6A-7, and T-6A-14; type 6B antibody rose, but variably. Upon challenge with 6B PS at age 3 yr, conjugate-primed children made anamnestic responses. T-6A-14, containing the longest saccharide chains (and highest saccharide:protein mass ratio) excelled in priming as well as antibody induction.
authors.affiliation: Department of Microbiology and Immunology, University of Rochester Medical Center, NY, USA.
authors.forename: M E
authors.initials: ME
authors.lastname: Pichichero
authors.forename: S
authors.initials: S
authors.lastname: Porcelli
authors.forename: J
authors.initials: J
authors.lastname: Treanor
authors.forename: P
authors.initials: P
authors.lastname: Anderson
mesh_terms: D000328:Adult; D000818:Animals; D000833:Animals, Suckling; D000907:Antibodies, Bacterial / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology* / Q000627:therapeutic use; D005260:Female; D006801:Humans; D007223:Infant; D051379:Mice; D011008:Pneumococcal Infections / Q000517:prevention & control; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D013296:Streptococcus pneumoniae / Q000276:immunology*; D014614:Vaccines, Synthetic / Q000276:immunology / Q000627:therapeutic use
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D011135:Polysaccharides, Bacterial; D014614:Vaccines, Synthetic