EPIDEMIOLOGICAL IMPACT OF MANDATORY VACCINATION AGAINST HEPATITIS B IN ITALIAN YOUNG ADULTS (BRIEF REPORT)

摘要

Background: Viral hepatitis caused by hepatitis B virus (HBV) is a leading cause of acute and chronic liver diseases worldwide.Objectives: 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-yearold adolescents was discontinued, and that of infants was maintained.Patients and 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.