title: 13-valent pneumococcal conjugate vaccine (PCV13) is immunogenic and safe in children 6-17 years of age with sickle cell disease previously vaccinated with 23-valent pneumococcal polysaccharide vaccine (PPSV23): Results of a phase 3 study.
abstract: BACKGROUND
  A large population of older children with sickle cell disease (SCD) is currently vaccinated with only 23-valent pneumococcal polysaccharide vaccine (PPSV23). In immunocompetent adults, PPSV23 vaccination reduces immune responses to subsequent vaccination with a pneumococcal vaccine. The 13-valent pneumococcal conjugate vaccine (PCV13), which addresses this limitation, may offer an advantage to this population at high risk of pneumococcal disease.
  
  
  METHODS
  Children with SCD 6-17 years of age previously vaccinated with PPSV23 at least 6 months before study enrollment received two doses of PCV13 6 months apart. Anti-pneumococcal polysaccharide immunoglobulin G (IgG) geometric mean concentrations (GMCs) and opsonophagocytic activity (OPA) geometric mean titers (GMTs) were measured before, 1 month after each administration, and 1 year after the second administration.
  
  
  RESULTS
  Following each PCV13 administration, IgG GMCs and OPA GMTs significantly increased, and antibody levels after doses 1 and 2 were generally comparable. Antibody levels declined over the year following dose 2. At 1 year after the second administration, OPA GMTs for all and IgG GMCs for most serotypes remained above pre-vaccination levels. Most adverse events were due to vaso-occlusive crises, a characteristic of the underlying condition of SCD.
  
  
  CONCLUSIONS
  Children with SCD who were previously vaccinated with PPSV23 responded well to 1 PCV13 dose, and a second dose did not increase antibody response. PCV13 antibodies persisted above pre-vaccination levels for all serotypes 1 year after dose 2. Children with SCD may benefit from at least one dose of PCV13.
authors: Hôpital Necker-Enfants Malades, Service de Pédiatrie, Paris, France.
authors: Mariane
authors: M
authors: De Montalembert
authors: Department of Pediatrics and Adolescent Medicine, American University of Beirut, Beirut, Lebanon.
authors: Miguel R
authors: MR
authors: Abboud
authors: Vaccine Research, Pfizer Ltd, Tadworth, Berkshire, UK.
authors: Anne
authors: A
authors: Fiquet
authors: RHUH, Rafic Hariri University Hospital, Beirut, Lebanon.
authors: Adlette
authors: A
authors: Inati
authors: University of Alabama at Birmingham, Birmingham, Alabama.
authors: Jeffrey D
authors: JD
authors: Lebensburger
authors: Pediatric Cairo University Hospital (Abu Elreesh - Almoneera), Egypt.
authors: Normeen
authors: N
authors: Kaddah
authors: Hematology unit, Children Hospital, Ain Shams University, Cairo, Egypt.
authors: Galila
authors: G
authors: Mokhtar
authors: Ospedale San Luigi Gonzaga, Orbassano, Torino University, Italy.
authors: Antonio
authors: A
authors: Piga
authors: Vanderbilt University Medical Center, Nashville, Tennessee.
authors: Natasha
authors: N
authors: Halasa
authors: Evelina Children's Hospital, St Thomas' Hospital, London, UK.
authors: Baba
authors: B
authors: Inusa
authors: King's College Hospital, London, UK.
authors: David C
authors: DC
authors: Rees
authors: Vaccine Institute, St Georges, University of London, London, UK.
authors: Paul T
authors: PT
authors: Heath
authors: Royal London Hospital, London, UK.
authors: Paul
authors: P
authors: Telfer
authors: Children's Hospital at Montefiore, Bronx, New York.
authors: Catherine
authors: C
authors: Driscoll
authors: King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
authors: Sami
authors: S
authors: Al Hajjar
authors: Unità Operativa di Epidemiologia Ospedale Bambino Gesù, Roma, Italy.
authors: Alberto
authors: A
authors: Tozzi
authors: Vaccines, Pfizer Inc, Collegeville, Pennsylvania.
authors: Qin
authors: Q
authors: Jiang
authors: Vaccine Research, Pfizer Inc, Pearl River, New York.
authors: Emilio A
authors: EA
authors: Emini
authors: Vaccine Research, Pfizer Inc, Pearl River, New York.
authors: William C
authors: WC
authors: Gruber
authors: Vaccine Research, Pfizer Inc, Pearl River, New York.
authors: Alejandra
authors: A
authors: Gurtman
authors: Vaccine Research, Pfizer Inc, Pearl River, New York.
authors: Daniel A
authors: DA
authors: Scott
mesh_terms: D000293:Adolescent; D000755:Anemia, Sickle Cell / Q000276:immunology*; D000907:Antibodies, Bacterial / Q000097:blood* / Q000276:immunology; D002648:Child; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D007074:Immunoglobulin G / Q000097:blood / Q000276:immunology; D008297:Male; D010587:Phagocytosis / Q000276:immunology; D011008:Pneumococcal Infections / Q000276:immunology / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000276:immunology*; D013296:Streptococcus pneumoniae / Q000276:immunology; D018074:Vaccines, Conjugate / Q000276:immunology*
chemical_list: C538862:13-valent pneumococcal vaccine; C414006:23-valent pneumococcal capsular polysaccharide vaccine; D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D022242:Pneumococcal Vaccines; D018074:Vaccines, Conjugate
keywords: 13-valent pneumococcal conjugate vaccine; 23-valent pneumococcal polysaccharide vaccine; hydroxycarbamide; immunogenicity; safety; sickle cell disease