A PILOT MODEL OF VACCINATION AGAINST HEPATITIS-B VIRUS SUITABLE FOR MASS VACCINATION CAMPAIGNS IN HYPERENDEMIC AREAS

A hepatitis B vaccination campaign was carried out in a town of 60,000 inhabitants, Afragola, Campania, Italy, a hyperendemic area for hepat itis B where HBsAg prevalence was 13.4% and anti-HBc prevalence was 64 .7%. This experimental pilot project aimed to reduce the incidence of both acute and asymptomatic viral hepatitis B and of related chronic l iver complications. From 1983-1989, 8,400 subjects were vaccinated: 6, 900 children up to 10 years of age and 1,500 subjects from 11-60 years of age. High seroconversion rates were observed: 99.0% in all childre n under one year of age, 96.0% in the older children, and 86.7% in adu lts. The rate of infection in Afragola has diminished from 63/100,000 in 1983 to 10/100,000 in 1989. Carriers of HBsAg decreased in the gene ral population (7.3% compared to 13.4%), especially in children up to 10 years of age (1.0% compared to 9.0%). In babies who received hepati tis B vaccine at the same time as compulsory vaccinations compliance w as 98% while it was 80% in babies who were vaccinated separately. In J une 1991 the Italian Parliament promulgated a decree which imposes hep atitis B vaccination for all newborn babies at 3, 5, and 11 months of age, at the same times as the mandatory childhood vaccinations (diphth eria, tetanus, and polio) according to a new protocol (Piazza scheme) which has been in use since January 1987 in our pilot vaccination camp aign in Afragola.