title: Pattern of functional antibody activity against Haemophilus influenzae type B (Hib) in infants immunized with diphtheria-tetanus-pertussis/Hib Brazilian combination vaccine.
abstract: We evaluated the functional activity of Haemophilus influenzae B (Hib) antibodies elicited in a group of infants immunized with the diphtheria-tetanus-pertussis vaccine combined with an Hib vaccine produced totally in Brazil after technological transfer of Hib vaccine production from Glaxo SmithKline, Belgium. Blood samples from immunized infants (N = 985) were collected for the determination of Hib antibodies. Total Ig and IgM and IgG subclasses of antibodies against polyribosyl ribitol phosphate (PRP) were analyzed by ELISA. Almost all vaccinees (97.56%, 961/985) developed a strong anti-PRP IgG antibody response (>or=1.0 microg/mL), while an anti-PRP IgM response was observed in 64.24% (634/985) of them (>or=0.15 microg/mL). Only 18.88% (186/985) of the infants in the group with high PRP antibody IgG concentrations (>or=1.0 microg/mL) developed a high IgM antibody response. Anti-PRP IgG antibody levels were significantly higher than anti-PRP IgM. These results demonstrate the predominance of IgG antibodies over IgM antibodies in response to PRP, with a ratio of 17:1. IgG antibodies were predominantly of the IgG1 subclass. An increase in IgG avidity was also observed during the course of immunization.
authors.affiliation: Laboratório de Tecnologia Imunológica, Fiocruz, Rio de Janeiro, RJ, Brasil.
authors.forename: D C S
authors.initials: DC
authors.lastname: Matos
authors.forename: A M V
authors.initials: AM
authors.lastname: Silva
authors.forename: P C C
authors.initials: PC
authors.lastname: Neves
authors.forename: R M
authors.initials: RM
authors.lastname: Martins
authors.forename: A
authors.initials: A
authors.lastname: Homma
authors.forename: R
authors.initials: R
authors.lastname: Marcovistz
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology*; D000915:Antibody Affinity / Q000276:immunology*; D016667:Bacterial Capsules / Q000276:immunology*; D015721:Diphtheria-Tetanus-Pertussis Vaccine / Q000276:immunology*; D004311:Double-Blind Method; D004797:Enzyme-Linked Immunosorbent Assay; D005500:Follow-Up Studies; D018073:Haemophilus Vaccines / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007075:Immunoglobulin M / Q000097:blood / Q000276:immunology; D007223:Infant; D011134:Polysaccharides / Q000276:immunology; D018074:Vaccines, Conjugate / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D015721:Diphtheria-Tetanus-Pertussis Vaccine; D018073:Haemophilus Vaccines; C044237:Haemophilus influenzae type b polysaccharide vaccine; D007074:Immunoglobulin G; D007075:Immunoglobulin M; D011134:Polysaccharides; D018074:Vaccines, Conjugate; C008984:polyribitol phosphate