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In 1992, 620 adolescents were vaccinated against hepatitis B. Anti-HBs concentrations were measured in 480 (77.4%) adolescents 1 month after completion of the primary course of vaccination. To assess the persistence of anti-HBs, 347 and 228 of such vaccinees were retested for anti-HBs in 1999 and for anti-HBs and anti-HBc in 2003. More than 10 years after vaccination, individuals with anti-HBsor=10 mIU/ml were considered protected while those with antibody10 mIU/ml were given a booster dose and retested 2 weeks later. Check performed in 2003 showed that 208/228 (91.2%) vaccinees retained protective concentrations of anti-HBs. All vaccinees were anti-HBc negative. 11 of the 12 (91.7%) individuals who were given a booster dose of vaccine showed a vigorous anamnestic response while the remaining one showed a weak response (10.6 mIU/ml). These data suggests that hepatitis B vaccination can confer long-term immunity and that immunological memory can outlast the loss of antibody. Hence, the use of routine booster doses of vaccine does not appear necessary to maintain long-term protection in successfully vaccinated immunocompetent individuals.

Although the secondary transmission of hepatitis A virus (HAV) infection is preventable through vaccination, it is not known whether the vaccination of household contacts is feasible. To this end, we conducted a prospective cohort study among the household contacts, 40 years of age or less, of all persons infected with primary HAV infection (index cases) and admitted to eight hospitals in southern Italy within 7 days of onset. Household contacts were vaccinated, and serum samples were taken at vaccination and after 14 and 45 days. Secondary cases were defined as those with IgM seroconversion occurring at least two weeks after enrolment. Coprimary cases were those assumed to have had the same exposure as the index case. Susceptible cases were those who were negative for both IgG and IgM. A total of 495 household contacts participated (acceptance rate of 65%); 65% were vaccinated within 4 days of admission of the index case and 95% within 7 days. At enrolment, 196 (39.6%) household contacts were immune (IgG-positive serum). During follow-up, 19 (3.8%) were IgM-positive: 13 (2.6%) were coprimary cases and 6 (1.2%; 95% CI: 0.2–3.2) secondary cases (5 identified at 14 days from vaccination and 1 at 45 days). Of the 241 susceptible cases, 192 (79.7%) had developed IgG antibodies at 14 days and only 3 (1.2%) did not develop IgG antibodies at 45 days. The 65% acceptance rate and the finding that 95% of the participating household contacts were vaccinated within 7 days of the index case's hospitalization indicate that timely vaccination is indeed feasible. The necessity of returning for the collection of blood samples probably decreased the acceptance rate.

The overall situation on viral hepatitis prevention and control in Italy was reviewed and evaluated at a Viral Hepatitis Prevention Board (VHPB) meeting in Catania, Sicily, on 7-8 November 2002. Several specific conclusions, drawn from the presentations and discussions, were considered to constitute an example of how to handle these issues in other European and industrialized countries.

The vaccination campaign against hepatitis B for 12-year-old subjects in Italy was evaluated in 136 health districts (USL); 55 in the north, 69 in the centre, and 12 in the south, respectively. Out of the 113, 230 eligible subjects born in 1981, 105, 989, (93.6%) completed the three dose series during the period 1993–1994. However, wide geographical differences are observed: the acceptance rate was as high as 97.9% (range 89.7–100.0) and 96.6% (range 76.0–100.0) in the north and in the centre, respectively; but only 65.1% in the south (range 26.8–100.0). Subjects were recruited in the north and in the centre mostly from the list of residents, while in the south more likely only from the list of people attending school. The school attendance in the south, not as good as in the other Italian areas, particularly among people belonging to a subgroup of the population economically disadvantaged, appears to be a strong determinant of the different vaccine coverage observed. Active efforts from health services in southern areas are necessary to reach subgroups of population who escape hepatitis B vaccination and who are also at high risk of HBV infection.

The effectiveness in the prevention of perinatally transmitted HBV infection was assessed in 11858 pregnant women consecutively recruited in public and private hospitals in six Italian regions during a 2 months period in 2001. Of them 10881 (91.8%) attended HBsAg antenatal screening. The overall HBsAg prevalence was 1.7% (CI 95%: 1.4-1.9); it was 1.4% (CI 95%: 1.2-1.7) in pregnant women born in Italy but 5.9% (CI 95%: 4.1-8.1) in those born in Asia, Africa, central and south America, and eastern Europe. Results of multiple logistic regression analysis indicate that birth in foreign countries (OR 2.0; CI 95%: 1.3-3.0), family size with more than 4 members in the household (OR 3.5; CI 95%:2.7-4.6), and birth in a private hospital (OR 1.9; CI 95%: 1.3-2.8) were all independent predictors of lack of adherence to HBsAg screening. Out of the 182 new-borns of HBsAg positive mothers 172 (95.0%) were given active plus passive immunisation; this figure was 100% in new-borns of foreign mothers. These findings evidence a good effectiveness in the prevention of perinatally transmitted HBV in Italy. More efforts should be addressed to improve the effectiveness of the programme among foreign pregnant women who have high rate of HBsAg and more likely escape HBsAg screening than Italian pregnant women.

In Italy, improved sanitation and living conditions have led to a decline in the rate of hepatitis A infection among children generating an increasing proportion of adults susceptible to this virus. Shellfish consumption is a major source of infection while person to person transmission is important in the spread of infection and in the maintenance of outbreaks. Thus prevention of secondary HAV infection is a crucial point. A randomised controlled trial of hepatitis A vaccine in household contacts of people with sporadic HAV infection in Italy has shown a protective efficacy of 82% (CI 20–96%). The two secondary infections in the vaccine group were symptomless, suggesting that the disease expression may be weaker in vaccinated subjects.

The ongoing vaccination campaign against hepatitis B (HB) for newborns of hepatitis B surface antigen (HBsAg) positive mothers and for 12-year-old subjects was evaluated in Naples, Italy, an area of relatively high HB endemicity. Subjects were recruited by a random sampling procedure. Among 2060 pregnant women studied, 1887 (91.6%) were screened for HBsAg. HBsAg prevalence was 2.5% ( 47 1887 ). Immunoprophylaxis according to the protocol (immunoglobulins within 24 h plus vaccine within 7 days after birth) was administered in 26 (55.3%) out of the 47 newborns of HBsAg positive mothers; vaccination was delayed (later than 7 days after birth) for 14 (29.8%) infants; in the remaining seven newborns (14.9%) were not given immunoglobulins at birth. All infants were vaccinated. Out of the 1000 adolescents sampled 130 (13%) were not found due to an inaccurate census list; 727 (83.3%) of the 870 investigated had received a three-dose HB vaccine series. Overall, the HB vaccination program in Italy is working well. However, further efforts should be made to improve the efficacy and effectiveness of the campaign.

In order to prevent hepatitis B virus (HBV) infection of infants of hepatitis B surface antigen (HBsAg)-positive mothers, a nation-wide immunization programme was initiated in Italy in January 1984. During the first 3 years (1984-86), 651,667 out of 1726,000 pregnant women (37.8%) were screened for HBsAg; the percentage of mothers screened increased from 32% in 1984 to 51% in 1986 in 15 of the 21 Italian regions, where data by year were available. HBsAg was present in 15,640 mothers (2.4% of those screened); range by region 0.3-6.4%. All newborns of HBsAg-positive women, regardless of the mother's status of hepatitis Be antigen (HBeAg), were given a single dose (0.5 ml Kg-1) of a hepatitis B immune globulin within 24 h after birth and the first dose of plasma-derived hepatitis B vaccine within 7 days after birth. The immunization coverage rate was 80% in the 3-year period. Protective antibodies were found in greater than 97% of a sample of 1071 infants, immunized from different regions. No serious reactions were observed. On the basis of this field experience, it may be concluded that a nation-wide hepatitis B vaccination programme for infants of HBsAg-carrier mothers would be highly immunogenic and safe. Its implementation, however, requires continuous public education and cooperation from physicians.