title: Safety and immunogenicity of neonatal pneumococcal conjugate vaccination in Papua New Guinean children: a randomised controlled trial.
abstract: BACKGROUND
  Approximately 826,000 children, mostly young infants, die annually from invasive pneumococcal disease. A 6-10-14-week schedule of pneumococcal conjugate vaccine (PCV) is efficacious but neonatal PCV may provide earlier protection and better coverage. We conducted an open randomized controlled trial in Papua New Guinea to compare safety, immunogenicity and priming for memory of 7-valent PCV (PCV7) given in a 0-1-2-month (neonatal) schedule with that of the routine 1-2-3-month (infant) schedule.
  
  
  METHODS
  We randomized 318 infants at birth to receive PCV7 in the neonatal or infant schedule or no PCV7. All infants received 23-valent pneumococcal polysaccharide vaccine (PPV) at age 9 months. Serotype-specific serum IgG for PCV7 (VT) serotypes and non-VT serotypes 2, 5 and 7F were measured at birth and 2, 3, 4, 9, 10 and 18 months of age. Primary outcomes were geometric mean concentrations (GMCs) and proportions with concentration ≥ 0.35 µg/ml of VT serotype-specific pneumococcal IgG at age 2 months and one month post-PPV.
  
  
  RESULTS
  We enrolled 101, 105 and 106 infants, respectively, into neonatal, infant and control groups. Despite high background levels of maternally derived antibody, both PCV7 groups had higher GMCs than controls at age 2 months for serotypes 4 (p<0.001) and 9V (p<0.05) and at age 3 months for all VTs except 6B. GMCs for serotypes 4, 9V, 18C and 19F were significantly higher (p<0.001) at age 2 months in the neonatal (one month post-dose2 PCV7) than in the infant group (one month post-dose1 PCV7). PPV induced significantly higher VT antibody responses in PCV7-primed than unprimed infants, with neonatal and infant groups equivalent. High VT and non-VT antibody concentrations generally persisted to age 18 months.
  
  
  CONCLUSIONS
  PCV7 is well-tolerated and immunogenic in PNG neonates and young infants and induces immunologic memory to PPV booster at age 9 months with antibody levels maintained to age 18 months.
  
  
  BACKGROUND
  ClinicalTrials.gov NCT00219401.
authors: Papua New Guinean Institute of Medical Research, Goroka, Papua New Guinea.
authors: William S
authors: WS
authors: Pomat
authors: Anita H J
authors: AH
authors: van den Biggelaar
authors: Suparat
authors: S
authors: Phuanukoonnon
authors: Jacinta
authors: J
authors: Francis
authors: Peter
authors: P
authors: Jacoby
authors: Peter M
authors: PM
authors: Siba
authors: Michael P
authors: MP
authors: Alpers
authors: John C
authors: JC
authors: Reeder
authors: Patrick G
authors: PG
authors: Holt
authors: Peter C
authors: PC
authors: Richmond
authors: Deborah
authors: D
authors: Lehmann
mesh_terms: D005260:Female; D006801:Humans; D007115:Immunization Schedule; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D011008:Pneumococcal Infections / Q000276:immunology* / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000009:adverse effects / Q000627:therapeutic use; D018074:Vaccines, Conjugate / Q000009:adverse effects / Q000627:therapeutic use*
chemical_list: C414006:23-valent pneumococcal capsular polysaccharide vaccine; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate