title: The effect of late doses on the achievement of seroprotection and antibody titer levels with hepatitis b immunization among adolescents.
abstract: OBJECTIVE
  To determine the effect of varying dosing schedules and predictor variables on the seroprotection rates and geometric mean titer levels resulting from the hepatitis B vaccination series among adolescents.
  
  
  METHODS
  Adolescents received the hepatitis B vaccination series at varying schedules according to their natural adherence patterns. Data collected included participants' medication use; chronic illness; use of cigarettes, alcohol, and marijuana; age; race/ethnicity; and body mass index. Participants' dates of vaccinations were recorded and titer levels for hepatitis B surface antibody were drawn ~12 and 24 months after study enrollment. The data for 498 participants were analyzed using chi(2) tests, Student t tests, logistic regression models, and analysis of variance.
  
  
  RESULTS
  Seroprotection rates among adolescents were not affected by late vaccinations. The only factors affecting the achievement of seroprotection ~12 and 24 months after the first vaccination were body mass index and the number of immunizations received. Increased time between doses 1 and 2 and doses 2 and 3 showed a trend toward correlating with increasing titer levels.
  
  
  CONCLUSIONS
  Although adolescents at risk of acquiring hepatitis B should receive the hepatitis B vaccination series in a timely fashion, late doses are not detrimental, and may be beneficial, to achieving high antibody levels against the hepatitis B virus.
authors.affiliation: Adolescent and Sports Medicine Section, Department of Pediatrics, Baylor College of Medicine, Houston, Texas, USA. amym@bcm.tmc.edu
authors.forename: A B
authors.initials: AB
authors.lastname: Middleman
authors.forename: C A
authors.initials: CA
authors.lastname: Kozinetz
authors.forename: L M
authors.initials: LM
authors.lastname: Robertson
authors.forename: R H
authors.initials: RH
authors.lastname: DuRant
authors.forename: S J
authors.initials: SJ
authors.lastname: Emans
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D005260:Female; D006510:Hepatitis B Antibodies / Q000096:biosynthesis*; D017325:Hepatitis B Vaccines / Q000008:administration & dosage* / Q000276:immunology*; D006801:Humans; D007115:Immunization Schedule; D016015:Logistic Models; D008297:Male
chemical_list: D006510:Hepatitis B Antibodies; D017325:Hepatitis B Vaccines