title: Epidemiological impact of mandatory vaccination against hepatitis B in Italian young adults.
abstract: BACKGROUND
  Viral hepatitis caused by hepatitis B virus (HBV) is a leading cause of acute and chronic liver diseases worldwide.
  
  
  OBJECTIVE
  In Italy, a mandatory vaccination policy was introduced in 1991 and was established for all newborns and 12-year-old individuals. In 2004, vaccination of 12-year old adolescents was discontinued, and that of infants was maintained.
  
  
  METHODS
  We evaluated the seroprevalence of HBV markers in 806 individuals, who were vaccinated at birth or at 12 years of age, to assess the effectiveness of the national policy against HBV.
  
  
  RESULTS
  The overall prevalence of anti-HBs antibodies was 90.32% (95% confidence interval [CI]: 88.28-92.36%); 2.23% (95% CI: 1.21-3.25%) of the subjects were positive for both antibodies to HBsAg (anti-HBs) and antibodies to hepatitis B core antigen (anti-HBc), whereas 5.83% (95% CI 4.21-7.45) of the subjects were negative for all markers tested. Further, 1.61% (95% CI: 0.74-2.48%) of the subjects were positive for hepatitis B surface antigen (HBsAg).
  
  
  CONCLUSIONS
  Our data provide additional evidence that HBV vaccination can confer long-term immunity when performed at birth and when performed for healthy adolescents; moreover, the results show the effectiveness of the application of a national vaccination strategy.
authors.affiliation: Department of Public Health, University of Cagliari, Cagliari, Italy.
authors.forename: Marcello
authors.initials: M
authors.lastname: Campagna
authors.forename: Andrea
authors.initials: A
authors.lastname: Siddu
authors.forename: Angelo
authors.initials: A
authors.lastname: Meloni
authors.forename: Claudia
authors.initials: C
authors.lastname: Murru
authors.forename: Giuseppina
authors.initials: G
authors.lastname: Masia
authors.forename: Rosa Cristina
authors.initials: RC
authors.lastname: Coppola