HEPATITIS-B MASS IMMUNIZATION OF ADOLESCENTS - A PILOT-STUDY IN A COMMUNITY

The National Type Specific Hepatitis Surveillance System (SEIEVA) and seroepidemiological studies have shown that in addition to newborns fr om mothers who are carriers for hepatitis B surface antigen (HBsAg), a dolescents are at high risk of acquiring type B hepatitis virus becaus e of increasing importance of the heterosexual transmission of this vi rus. In order to evaluate logistic problems and acceptance rate of ado lescents to mass vaccination against hepatitis B, a pilot study was ca rried out among all 7th grade children registered in the 9 schools of an hepatitis B endemic area located in the suburbs of Naples. After me etings held by the local health department with school teachers and pa rents, 1219 out of 1250 (97.5%) invited children received the first do se of hepatitis B vaccine; 1215 and 1209 received, respectively, the s econd and third doses. Anti-hepatitis B surface antigen (anti-HBs) val ues were studied in 406 subjects one month after the third dose, and 2 1 out of 406 (5.2%) had anti-HBs values less than 10 IU/L. We consider 95% of subjects with anti-HBs values greater than 9 IU/L a good achie vement for a field vaccination program. The high acceptance rate of va ccination found in our study outlines the importance of active offer o f vaccination combined with school involvement.