title: Immunogenicity and safety of a 13-valent pneumococcal conjugate vaccine in adults 70 years of age and older previously vaccinated with 23-valent pneumococcal polysaccharide vaccine.
abstract: BACKGROUND
  The currently recommended single dose of the 23-valent pneumococcal free polysaccharide vaccine (PPSV23) for adults 65 years of age and older does not provide extended protection into older age. This reflects a significant unmet medical need for alternative strategies to protect older adults against pneumococcal infection, which may be met by the 13-valent polysaccharide conjugate vaccine (PCV13).
  
  
  METHODS
  We performed a randomized, modified double-blind trial in 936 adults aged 70 years and older who had previously received PPSV23 at least 5 years before study entry and were now vaccinated with PCV13 or PPSV23. At 1 year after enrollment, all subjects received a follow-on dose of PCV13. Anti-pneumococcal opsonophagocytic activity (OPA) titers were measured before and at 1 month after each vaccination.
  
  
  RESULTS
  Following the enrollment vaccination, OPA titers were significantly greater in the PCV13 group compared to the PPSV23 group for 10 of the 12 serotypes common to both vaccines and to serotype 6A which is unique to PCV13. Responses were noninferior for the other 2 common serotypes. Responses to PCV13 given at 1 year were generally lower in the group that received PPSV23 at enrollment.
  
  
  CONCLUSIONS
  In adults aged 70 years and older previously vaccinated with PPSV23, PCV13 was significantly more immunogenic than PPSV23 for most of the common serotypes and for serotype 6A. The OPA responses after a follow-on dose of PCV13 one year later indicate that a prior dose of PPSV23, but not PCV13, diminishes the response to the subsequent administration of PCV13.
authors.affiliation: The Group Health Research Institute, Group Health, Seattle, WA, USA. jackson.l@ghc.org
authors.forename: Lisa A
authors.initials: LA
authors.lastname: Jackson
authors.forename: Alejandra
authors.initials: A
authors.lastname: Gurtman
authors.forename: Kathryn
authors.initials: K
authors.lastname: Rice
authors.forename: Karlis
authors.initials: K
authors.lastname: Pauksens
authors.forename: Richard N
authors.initials: RN
authors.lastname: Greenberg
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Jones
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Scott
authors.forename: Emilio A
authors.initials: EA
authors.lastname: Emini
authors.forename: William C
authors.initials: WC
authors.lastname: Gruber
authors.forename: Beate
authors.initials: B
authors.lastname: Schmoele-Thoma
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000907:Antibodies, Bacterial / Q000097:blood; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D008297:Male; D022242:Pneumococcal Vaccines / Q000009:adverse effects / Q000276:immunology / Q000627:therapeutic use; D011018:Pneumonia, Pneumococcal / Q000276:immunology / Q000517:prevention & control*; D011135:Polysaccharides, Bacterial / Q000276:immunology; D013296:Streptococcus pneumoniae / Q000276:immunology*; D014481:United States; D018074:Vaccines, Conjugate / Q000009:adverse effects / Q000276:immunology / Q000627:therapeutic use
chemical_list: C538862:13-valent pneumococcal vaccine; C414006:23-valent pneumococcal capsular polysaccharide vaccine; D000907:Antibodies, Bacterial; D022242:Pneumococcal Vaccines; D011135:Polysaccharides, Bacterial; D018074:Vaccines, Conjugate
keywords: 13-valent pneumococcal conjugate vaccine; 23-valent polysaccharide vaccine; ACIP; AE; Adults; CI; CRM(197); GMR; GMT; ITP; OPA; PCV; PCV13; PPSV23; Pneumococcal conjugate vaccine; RCDC; SAE; United States Advisory Committee on Immunization Practices; adverse event; confidence interval; cross-reactive material 197; geometric mean ratio; geometric mean titer; idiopathic thrombocytopenic purpura; opsonophagocytic activity; pneumococcal polysaccharide conjugate vaccine; reverse cumulative distribution curve; serious adverse event