title: Immunogenicity of a 2-dose priming and booster vaccination with the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine.
abstract: BACKGROUND
  The immunogenicity of the 10-valent pneumococcal nontypeable Haemophilus influenzae protein D-conjugate vaccine (PHiD-CV) was determined following a simplified 2-dose priming and the more commonly employed 3-dose priming both followed by a booster dose.
  
  
  METHODS
  A total of 351 healthy subjects were primed with PHiD-CV at either 3 and 5 or 3, 4 and 5 months of age followed in all subjects by a booster dose at 11 to 12 months of age. Serotype-specific pneumococcal responses were measured by 22F-inhibition ELISA and opsonophagocytic assays 1 month following primary and booster vaccinations.
  
  
  RESULTS
  Depending on the serotype, the percentages of subjects reaching the ELISA antibody threshold of 0.2 microg/mL were 92.8% to 98.0% following 2 primary doses and 96.1% to 100% following 3 primary doses except for serotype 6B (55.7% and 63.1%, respectively) and serotype 23F (69.3% and 77.6%, respectively). Opsonophagocytic activity (OPA) could be measured in 74.4% to 100% and 88.9% to 100% of the subjects after the 2-dose or 3-dose priming, respectively, except for serotype 1 (60.8% and 62.9%, respectively). In both groups, robust increases in ELISA antibodies and OPA titers were observed for all serotypes after the booster dose. Higher postprimary and postbooster ELISA antibody levels and OPA titers were observed for most serotypes following the 3+1 schedule.
  
  
  CONCLUSIONS
  PHiD-CV was immunogenic in both schedules, but further effectiveness data are needed to fully understand the public health benefit to be expected from these schedules in terms of prevention against invasive and mucosal infections.
authors.affiliation: Department of Clinical Sciences, Pediatrics, Umeå University, Umeå, Sweden. sven.arne.silfverdal@pediatri.umu.se
authors.forename: Sven Arne
authors.initials: SA
authors.lastname: Silfverdal
authors.forename: Birthe
authors.initials: B
authors.lastname: Hogh
authors.forename: Marianne Riise
authors.initials: MR
authors.lastname: Bergsaker
authors.forename: Helena
authors.initials: H
authors.lastname: Skerlikova
authors.forename: Patricia
authors.initials: P
authors.lastname: Lommel
authors.forename: Dorota
authors.initials: D
authors.lastname: Borys
authors.forename: Lode
authors.initials: L
authors.lastname: Schuerman
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D001426:Bacterial Proteins / Q000276:immunology*; D002352:Carrier Proteins / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D018073:Haemophilus Vaccines / Q000276:immunology*; D006801:Humans; D007117:Immunization, Secondary / Q000379:methods*; D007072:Immunoglobulin D / Q000276:immunology*; D007223:Infant; D008074:Lipoproteins / Q000276:immunology*; D008297:Male; D009895:Opsonin Proteins / Q000097:blood; D010587:Phagocytosis; D022242:Pneumococcal Vaccines / Q000276:immunology*; D014611:Vaccination / Q000379:methods*; D018074:Vaccines, Conjugate / Q000276:immunology
chemical_list: C538863:10-valent pneumococcal vaccine; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D018073:Haemophilus Vaccines; D007072:Immunoglobulin D; D008074:Lipoproteins; D009895:Opsonin Proteins; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate; C067989:glpQ protein, Haemophilus influenzae