title: Long-term immunogenicity of hepatitis B vaccination in children and adolescents in a southern Italian town.
abstract: OBJECTIVE
  Universal anti-hepatitis B vaccination of infants and of 12-year-old children became mandatory in Italy in 1991. The purpose of this study was to evaluate the persistence of anti-hepatitis B surface (HBs) antibodies several years after a primary course of vaccination.
  
  
  METHODS
  In 2010, anti-HBs titers were measured in all subjects aged between 5 and 25 years residing in a southern Italian town. Individuals with an anti-hepatitis B antibody concentration of 10 IU/ml or more were considered to be protected.
  
  
  RESULTS
  Of the 671 subjects evaluated, 149 (30%) lacked protective antibodies. Fifty-three (29.4%) of the subjects had been vaccinated ≤10 years earlier and 96 (30.3%) more than 10 years earlier (P = not significant). Subjects vaccinated in infancy were more likely to lack protective anti-HBs antibodies than subjects vaccinated at 12 years of age, regardless of the years elapsed since immunization.
  
  
  CONCLUSIONS
  Most subjects maintained protective antibodies for a considerable number of years after vaccination. Vaccination in adolescence results in more prolonged immunogenicity than vaccination in infancy.
authors.affiliation: Department of Infectious and Tropical Diseases, Institute of Tropical Diseases, Policlinico Umberto I, Viale del Policlinico 155, 00161, Rome, Italy. t.stroffolini@policlinicoumberto1.it
authors.forename: T
authors.initials: T
authors.lastname: Stroffolini
authors.forename: V
authors.initials: V
authors.lastname: Guadagnino
authors.forename: B
authors.initials: B
authors.lastname: Caroleo
authors.forename: G
authors.initials: G
authors.lastname: De Sarro
authors.forename: A
authors.initials: A
authors.lastname: Focà
authors.forename: M C
authors.initials: MC
authors.lastname: Liberto
authors.forename: A
authors.initials: A
authors.lastname: Giancotti
authors.forename: G S
authors.initials: GS
authors.lastname: Barreca
authors.forename: N
authors.initials: N
authors.lastname: Marascio
authors.forename: F L
authors.initials: FL
authors.lastname: Lombardo
authors.forename: O
authors.initials: O
authors.lastname: Staltari
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006509:Hepatitis B / Q000276:immunology* / Q000517:prevention & control; D006510:Hepatitis B Antibodies / Q000097:blood*; D006512:Hepatitis B Core Antigens / Q000097:blood / Q000276:immunology; D006514:Hepatitis B Surface Antigens / Q000097:blood / Q000276:immunology; D017325:Hepatitis B Vaccines / Q000008:administration & dosage / Q000276:immunology*; D006515:Hepatitis B virus / Q000302:isolation & purification; D006801:Humans; D007558:Italy; D008297:Male; D013997:Time Factors; D055815:Young Adult
chemical_list: D006510:Hepatitis B Antibodies; D006512:Hepatitis B Core Antigens; D006514:Hepatitis B Surface Antigens; D017325:Hepatitis B Vaccines