title: Pneumococcal conjugate vaccine given shortly after birth stimulates effective antibody concentrations and primes immunological memory for sustained infant protection.
abstract: BACKGROUND
  In developing countries, newborn immunization with pneumococcal conjugate vaccines (PCVs) could protect young infants who are at high risk of invasive pneumococcal disease (IPD) but might lead to immune tolerance.
  
  
  METHODS
  In a randomized trial, young infants received 7-valent PCV at 6, 10, and 14 weeks (Expanded Programme on Immunization [EPI] group) or 0, 10, and 14 weeks (newborn group). Safety was monitored actively at 2-7 days and then passively. Serum samples obtained at birth and 6, 10, 14, 18, 36, and 37 weeks were assayed by enzyme-linked immunosorbent assay for anticapsular immunoglobulin G concentration and avidity. Infants were boosted with either 7-valent PCV or one-fifth dose of pneumococcal polysaccharide vaccine at 36 weeks. Nasopharyngeal swab samples were obtained at 18 and 36 weeks.
  
  
  RESULTS
  Three-hundred neonates and young infants were enrolled. Newborn vaccination was well tolerated. Adverse events occurred equally in each group; none was related to immunization. One infant, immunized at birth, died of unrelated neonatal sepsis. At 18 weeks, protective concentrations (≥0.35 μg/mL) were achieved against each serotype by ≥87% of infants with no significant differences between groups. Geometric mean concentrations were higher in the EPI group for serotypes 4, 9V, 18C, and 19F at 18 weeks and for serotype 4 at 36 weeks. Avidity was greater in the newborn group for serotypes 4, 6B, and 19F at 18 weeks and for serotype 19F at 36 weeks. Booster responses and vaccine-type/nonvaccine-type carriage prevalence did not differ between groups.
  
  
  CONCLUSIONS
  PCV was safe, immunogenic, and primed for memory when given at birth. There was no evidence of immune tolerance. Vaccination beginning at birth offers an alternative to control IPD in vulnerable young infants.
authors.affiliation: Kenya Medical Research Institute-Wellcome Trust Research Programme, Kilifi, Kenya. ascott@ikilifi.org
authors.forename: J Anthony G
authors.initials: JA
authors.lastname: Scott
authors.forename: John
authors.initials: J
authors.lastname: Ojal
authors.forename: Lindsey
authors.initials: L
authors.lastname: Ashton
authors.forename: Anne
authors.initials: A
authors.lastname: Muhoro
authors.forename: Polly
authors.initials: P
authors.lastname: Burbidge
authors.forename: David
authors.initials: D
authors.lastname: Goldblatt
mesh_terms: D000328:Adult; D000907:Antibodies, Bacterial / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D006801:Humans; D007117:Immunization, Secondary / Q000379:methods; D007074:Immunoglobulin G / Q000097:blood; D007156:Immunologic Memory; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009305:Nasopharynx / Q000382:microbiology; D022242:Pneumococcal Vaccines / Q000008:administration & dosage* / Q000009:adverse effects / Q000276:immunology*; D011247:Pregnancy; D014611:Vaccination / Q000379:methods
chemical_list: D000907:Antibodies, Bacterial; D000069443:Heptavalent Pneumococcal Conjugate Vaccine; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines