title: Immunogenicity and safety of a 13-valent pneumococcal conjugate vaccine in healthy infants in Japan.
abstract: BACKGROUND
  A 13-valent pneumococcal conjugate vaccine (PCV13) containing 6 additional serotypes not included in the 7-valent PCV has been developed to broaden protection against Streptococcus pneumoniae, which is responsible for over 500,000 deaths annually worldwide in children <5 years of age. This study in Japanese infants evaluated the immunogenicity and safety of PCV13 given subcutaneously, the standard route for infant vaccination in Japan.
  
  
  METHODS
  This phase 3, single-arm, open-label study was conducted at 25 sites. Subjects received PCV13 as a 3-dose infant series and a toddler dose. Parents/legal guardians recorded local reactions and systemic events after each vaccination. The proportion of subjects with serotype-specific antipneumococcal polysaccharide immunoglobulin (Ig)G antibody concentrations ≥0.35 µg/mL was calculated before and 1 month after the infant series and toddler dose.
  
  
  RESULTS
  A total of 193 subjects enrolled. The proportion of subjects achieving pneumococcal IgG antibody concentrations ≥0.35 µg/mL was ≥97.2% for all 13 pneumococcal serotypes 1 month after the infant series and 98.9-100% after the toddler dose. IgG geometric mean concentrations were 2.57-14.69 µg/mL after the infant series and 2.06-16.33 µg/mL after the toddler dose. IgG geometric mean concentrations increased from pre- to posttoddler dose by ≥2.8-fold, demonstrating a booster effect. Local reactions and fever were generally mild or moderate in severity.
  
  
  CONCLUSIONS
  PCV13 was immunogenic for all serotypes and had a favorable safety profile when administered subcutaneously to Japanese infants. PCV13 should offer broader serotype protection than 7-valent PCV in preventing pneumococcal disease in Japanese children.
authors.affiliation: From the *Department of Nursing, Sapporo City University, Sapporo; †Pfizer Inc, Tokyo, Japan; ‡Research, Pfizer Inc, Pearl River, NY; and §Research, Pfizer Inc, Collegeville, PA.
authors.forename: Takehiro
authors.initials: T
authors.lastname: Togashi
authors.forename: Masako
authors.initials: M
authors.lastname: Yamaji
authors.forename: Allison
authors.initials: A
authors.lastname: Thompson
authors.forename: Peter C
authors.initials: PC
authors.lastname: Giardina
authors.forename: Masakazu
authors.initials: M
authors.lastname: Aizawa
authors.forename: Scott
authors.initials: S
authors.lastname: Patterson
authors.forename: William C
authors.initials: WC
authors.lastname: Gruber
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Scott
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood; D064420:Drug-Related Side Effects and Adverse Reactions / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007223:Infant; D007279:Injections, Subcutaneous; D007564:Japan / Q000453:epidemiology; D008297:Male; D011008:Pneumococcal Infections / Q000453:epidemiology* / Q000382:microbiology / Q000517:prevention & control*; D022242:Pneumococcal Vaccines / Q000008:administration & dosage / Q000009:adverse effects* / Q000276:immunology*; D013296:Streptococcus pneumoniae / Q000276:immunology*; D018074:Vaccines, Conjugate / Q000008:administration & dosage / Q000009:adverse effects / Q000276:immunology
chemical_list: C538862:13-valent pneumococcal vaccine; D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate