title: Anamnestic immune response in 3- to 4-year-old children previously immunized with 10-valent pneumococcal nontypeable Haemophilus influenzae protein D conjugate vaccine as 2-dose or 3-dose priming and a booster dose in the first year of life.
abstract: BACKGROUND
  Immunogenicity of 10-valent pneumococcal nontypeable Haemophilus influenzae protein d conjugate vaccine (PHiD-CV), administered as 2-dose or 3-dose priming followed by a booster dose, has been described previously. The present study evaluated immunologic memory following PHiD-CV vaccination according to these vaccination schedules.
  
  
  METHODS
  A dose of PHiD-CV (to test anamnestic responses) was administered to 172 children at 36 to 46 months of age; 110 of them had previously been vaccinated with PHiD-CV according to 2 + 1 or 3 + 1 schedules (PHiD-CV [2 + 1] and PHiD-CV [3 + 1] groups) and 62 were unprimed age-matched controls. To measure immune responses before and 7 to 10 days after the PHiD-CV dose, 22F-inhibition enzyme-linked immunosorbent assay and opsonophagocytic activity (OPA) assay were used.
  
  
  RESULTS
  Serotype-specific IgG geometric mean concentrations (GMCs) and OPA geometric mean titers increased substantially (from before to 7 to 10 days after the additional PHiD-CV dose) for all 10 vaccines and 2 cross-reactive serotypes (6A and 19A) in the children previously vaccinated with PHiD-CV, regardless of the vaccination schedule used. Antibody GMCs and OPA geometric mean titers after the administration of the PHiD-CV dose were markedly higher in both previously PHiD-CV-vaccinated groups than in the unprimed control group, clearly demonstrating prior induction of immunologic memory. Antiprotein D antibody GMCs had also increased substantially from before to 7 to 10 days after vaccination in all 3 groups, with higher antibody GMCs in the previously vaccinated groups than in the control group.
  
  
  CONCLUSIONS
  PHiD-CV vaccination according to 2 + 1 or 3 + 1 schedules resulted in comparable anamnestic immune responses. These findings suggest that similar protective efficacy may be achieved with both the schedules.
authors.affiliation: Department of Clinical Sciences, Pediatrics, Umeå University, Sweden. silfverdal@pediatri.umu.se
authors.forename: Sven Arne
authors.initials: SA
authors.lastname: Silfverdal
authors.forename: Helena
authors.initials: H
authors.lastname: Skerlikova
authors.forename: Maria
authors.initials: M
authors.lastname: Zanova
authors.forename: Danica
authors.initials: D
authors.lastname: Papúchová
authors.forename: Magali
authors.initials: M
authors.lastname: Traskine
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 / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology*; D002352:Carrier Proteins / Q000276:immunology*; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007072:Immunoglobulin D / Q000276:immunology*; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D007156:Immunologic Memory / Q000276:immunology; D008074:Lipoproteins / Q000276:immunology*; D008297:Male; D011008:Pneumococcal Infections / Q000276:immunology* / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*; D013997:Time Factors; D014611:Vaccination; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
chemical_list: C538863:10-valent pneumococcal vaccine; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D002352:Carrier Proteins; D007072:Immunoglobulin D; D007074:Immunoglobulin G; D008074:Lipoproteins; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate; C067989:glpQ protein, Haemophilus influenzae