title: Comparative safety and immunogenicity of two recombinant hepatitis B vaccines given to infants at two, four and six months of age.
abstract: OBJECTIVE
  To evaluate the relative safety and immunogenicity of the two recombinant hepatitis B vaccines licensed in the United States with doses recommended for routine immunization of low risk infants and a schedule that corresponds with routine pediatric visits.
  
  
  METHODS
  Healthy infants were immunized at 2, 4 and 6 months of age with hepatitis B vaccine manufactured by either SmithKline Beecham (Engerix-B, 10 micrograms/dose, n = 228) or Merck and Co. (Recombivax HB, 2.5 micrograms/dose, n = 200). Adverse reactions were ascertained by parental reports and interviews and by review of medical records. Antibody concentrations to hepatitis B surface antigen (anti-HBs) were measured in sequential serum specimens by enzyme immunoassay.
  
  
  RESULTS
  Adverse reactions were mild and the rates were not significantly different between the two groups. After the first and second doses the rates of seropositivity (> or = 10 mIU/ml) and seroprotection (> or = 10 mIU/ml) were significantly higher in infants given SmithKline Beecham vaccine (P < 0.01). After the second and third doses infants given SmithKline Beecham vaccine also had significantly higher geometric mean anti-HBs concentrations compared with those given Merck vaccine (348.0 mIU/ml vs. 66.9 and 1914.8 mIU/ml vs. 514.8 mIU/ml, respectively, P < 0.001). Nevertheless after the third dose 99% of infants in both vaccine groups achieved seroprotective antibody concentrations.
  
  
  CONCLUSIONS
  Both recombinant hepatitis B vaccines were safe and immunogenic when administered concurrently with other pediatric vaccines at 2, 4 and 6 months of age, but earlier protective responses were observed with the SmithKline Beecham vaccine than with the Merck vaccine.
authors.affiliation: UCLA Center for Vaccine Research, Harbor-UCLA, Medical Center, Torrance, USA. Greenberg@harbor2.humc.edu
authors.forename: D P
authors.initials: DP
authors.lastname: Greenberg
authors.forename: C M
authors.initials: CM
authors.lastname: Vadheim
authors.forename: V K
authors.initials: VK
authors.lastname: Wong
authors.forename: S M
authors.initials: SM
authors.lastname: Marcy
authors.forename: S
authors.initials: S
authors.lastname: Partridge
authors.forename: T
authors.initials: T
authors.lastname: Greene
authors.forename: C Y
authors.initials: CY
authors.lastname: Chiu
authors.forename: H S
authors.initials: HS
authors.lastname: Margolis
authors.forename: J I
authors.initials: JI
authors.lastname: Ward
mesh_terms: D003257:Consumer Product Safety; D005260:Female; D006509:Hepatitis B / Q000276:immunology / Q000517:prevention & control; D006510:Hepatitis B Antibodies / Q000032:analysis; D017325:Hepatitis B Vaccines / Q000008:administration & dosage* / Q000009:adverse effects; D006801:Humans; D007115:Immunization Schedule; D007223:Infant; D008297:Male; D014614:Vaccines, Synthetic / Q000008:administration & dosage* / Q000009:adverse effects
chemical_list: D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines; D014614:Vaccines, Synthetic