title: Serotype-specific immunoglobulin G antibody responses to pneumococcal polysaccharide vaccine in children with sickle cell anemia: effects of continued penicillin prophylaxis.
abstract: OBJECTIVE
  (1) To determine serotype-specific IgG antibody responses to reimmunization with pneumococcal polysaccharide vaccine at age 5 years in children with sickle cell anemia and (2) to determine whether continued penicillin prophylaxis had any adverse effects on these responses.
  
  
  METHODS
  Children with sickle cell anemia, who had been treated with prophylactic penicillin for at least 2 years before their fifth birthday, were randomly selected at age 5 years to continue penicillin prophylaxis or to receive placebo treatment. These children had been immunized once or twice in early childhood with pneumococcal polysaccharide vaccine and were reimmunized at the time of randomization.
  
  
  RESULTS
  Serotype-specific IgG antibody responses to reimmunization varied according to pneumococcal serotype but in general were mediocre or poor; the poorest response was to serotype 6B. The antibody responses were similar in subjects with continued penicillin prophylaxis or placebo treatment, and in subjects who received one or two pneumococcal vaccinations before reimmunization. The occurrence of pneumococcal bacteremia was associated with low IgG antibody concentrations to the infecting serotype.
  
  
  CONCLUSIONS
  Reimmunization of children with sickle cell anemia who received pneumococcal polysaccharide vaccine at age 5 years induces limited production of serotype-specific IgG antibodies, regardless of previous pneumococcal vaccine history. Continued penicillin prophylaxis does not interfere with serotype-specific IgG antibody responses to reimmunization.
authors.affiliation: Division of Immunology, James N. Gamble Institute of Medical Research, Cincinnati, Ohio, USA.
authors.forename: A B
authors.initials: AB
authors.lastname: Bjornson
authors.forename: J M
authors.initials: JM
authors.lastname: Falletta
authors.forename: J I
authors.initials: JI
authors.lastname: Verter
authors.forename: G R
authors.initials: GR
authors.lastname: Buchanan
authors.forename: S T
authors.initials: ST
authors.lastname: Miller
authors.forename: C H
authors.initials: CH
authors.lastname: Pegelow
authors.forename: R V
authors.initials: RV
authors.lastname: Iyer
authors.forename: H S
authors.initials: HS
authors.lastname: Johnstone
authors.forename: M R
authors.initials: MR
authors.lastname: DeBaun
authors.forename: D L
authors.initials: DL
authors.lastname: Wethers
authors.forename: W C
authors.initials: WC
authors.lastname: Wang
authors.forename: G M
authors.initials: GM
authors.lastname: Woods
authors.forename: C T
authors.initials: CT
authors.lastname: Holbrook
authors.forename: D L
authors.initials: DL
authors.lastname: Becton
authors.forename: T R
authors.initials: TR
authors.lastname: Kinney
authors.forename: G H
authors.initials: GH
authors.lastname: Reaman
authors.forename: K
authors.initials: K
authors.lastname: Kalinyak
authors.forename: N J
authors.initials: NJ
authors.lastname: Grossman
authors.forename: E
authors.initials: E
authors.lastname: Vichinsky
authors.forename: C D
authors.initials: CD
authors.lastname: Reid
mesh_terms: D000328:Adult; D000755:Anemia, Sickle Cell / Q000150:complications / Q000276:immunology*; D000907:Antibodies, Bacterial / Q000097:blood*; D000918:Antibody Specificity; D001428:Bacterial Vaccines / Q000008:administration & dosage / Q000276:immunology*; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007117:Immunization, Secondary; D007074:Immunoglobulin G / Q000097:blood*; D008297:Male; D010406:Penicillins / Q000009:adverse effects / Q000627:therapeutic use*; D011008:Pneumococcal Infections / Q000209:etiology / Q000276:immunology / Q000517:prevention & control*; D011135:Polysaccharides, Bacterial / Q000276:immunology*; D012703:Serotyping; D013296:Streptococcus pneumoniae / Q000145:classification / Q000276:immunology*; D017086:beta-Thalassemia / Q000150:complications / Q000276:immunology
chemical_list: D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D007074:Immunoglobulin G; D010406:Penicillins; D011135:Polysaccharides, Bacterial