title: Long-term efficacy of plasma-derived and recombinant hepatitis B vaccines in a rural township of Central Taiwan.
abstract: OBJECTIVE
  To assess the differences of long-term efficacy between plasma-derived and recombinant hepatitis B virus (HBV) vaccines and the effectiveness of catch-up vaccination in adolescents with undetectable anti-HBs.
  
  
  METHODS
  Before 1992, infants born in Taiwan were immunized using plasma-derived HB vaccine, and thereafter, by using recombinant HB vaccine. From the only junior middle school of a rural township in central-southern Taiwan, 1788 (93.7%) students from five cross-sectional screenings, grouping into three birth cohorts (Group I: born during 1984-1986, II: 1986-1992 and III: 1992-1995), were enrolled for checking HBsAg, anti-HBs and anti-HBc. Students with undetectable HBsAg and anti-HBs underwent a booster dose (2.5ug) of recombinant HB vaccine (Engerix-B; GlaxoSmithKline, Rixensart, Belgium) and had anti-HBs re-checked 3 weeks later. Individuals who had remained undetectable for anti-HBs completed the other two doses of HB vaccines at 1 and 6 months later.
  
  
  RESULTS
  The prevalence of HBsAg (11.4, 5.4 and 1.2%), anti-HBs (64.5, 44.1 and 36.0%) and anti-HBc (29.5, 12.5 and 4.4%) decreased from Group I to III (P<0.001 for trends). After a booster dose, the positive rates of anti-HBs increased up to 80.5% (16% increase) in Group I, 81.0% (36.9% increase) in Group II, and 94.4% (58.4% increase) in Group III. The percentages of anamnestic response increased with a trend (P<0.001). A total of 110 non-responders completed 3 doses of catch-up HB vaccination, but 3 cases (2.7%) of Group II, evoked primary vaccination response.
  
  
  CONCLUSIONS
  Recombinant vaccine showed predominant disappearance rate (62.7%) of anti-HBs 12-15 years after vaccination, but provided better anamnestic response after a booster dose. It also showed high success rate (97.3%) in catch-up vaccination in adolescents.
authors.affiliation: Department of Internal Medicine, Chang Gung Memorial Hospital - Kaohsiung Medical Center, Chang Gung University College of Medicine, Kaohsiung, Taiwan.
authors.forename: Jung-Ta
authors.initials: JT
authors.lastname: Kao
authors.forename: Jing-Houng
authors.initials: JH
authors.lastname: Wang
authors.forename: Chao-Hung
authors.initials: CH
authors.lastname: Hung
authors.forename: Yi-Hao
authors.initials: YH
authors.lastname: Yen
authors.forename: Shu-Fen
authors.initials: SF
authors.lastname: Hung
authors.forename: Tsung-Hui
authors.initials: TH
authors.lastname: Hu
authors.forename: Chuan-Mo
authors.initials: CM
authors.lastname: Lee
authors.forename: Sheng-Nan
authors.initials: SN
authors.lastname: Lu
mesh_terms: D000293:Adolescent; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D019353:Endemic Diseases; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006509:Hepatitis B / Q000276:immunology*; D006514:Hepatitis B Surface Antigens / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000627:therapeutic use*; D006801:Humans; D007115:Immunization Schedule; D007117:Immunization, Secondary; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D013624:Taiwan; D014614:Vaccines, Synthetic
chemical_list: D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines; D014614:Vaccines, Synthetic