Hepatitis B immunity in teenagers vaccinated as infants: an Italian 17-year follow-up study.

We assessed the persistence of hepatitis B surface antigen antibody (anti-HBs) and immune memory in a cohort of 571 teenagers vaccinated against hepatitis B as infants, 17 years earlier. Vaccinees were followed-up in 2003 and in 2010 (i.e. 10 years and 17 years after primary vaccination, respectively). When tested in 2003, 199 vaccinees (group A) had anti-HBs <10 mIU/mL and were boosted, 372 (group B) were not boosted because they had anti-HBs ≥10 mIU/mL (n = 344) or refused booster (n = 28) despite anti-HBs <10 mIU/mL. In 2010, 72.9% (416/571) of participants had anti-HBs ≥10 mIU/mL (67.3% in group A vs. 75.8% in group B; p 0.03). The geometric mean concentrations (GMCs) were similar in both groups. Between 2003 and 2010, anti-HBs concentrations in previously boosted individuals markedly declined with GMC dropping from 486 to 27.7 mIU/mL (p <0.001). Fifteen vaccinees showed a marked increase of antibody, possibly due to natural booster. In 2010, 96 individuals (37 of group A and 59 of group B) with anti-HBs <10 mIU/mL were boosted; all vaccinees of the former group and all but two of the latter had an anamnestic response. Post-booster GMC was higher in group B (895.6 vs. 492.2 mIU/mL; p 0.039). This finding shows that the immune memory for HBsAg persists beyond the time at which anti-HBs disappears, conferring long-term protection.

Immunogenicity and effectiveness of virosomal adjuvanted vaccines against influenza: a brief review of their utility in the elderly population.

The World Health Organisation (WHO) estimates that seasonal influenza affects approximately 5-15% of the population on an annual basis and these outbreaks are responsible for significant morbidity and mortality resulting in increased hospital admissions. Annual vaccination remains the main public health strategy for containing influenza. Inactivated influenza vaccines offer a great deal of protection against influenza but these vaccines are not optimal for older adults due to their waning immunity and other factors affecting immunogenicity. Virosomes, stimulate the immune system in a similar way as a natural infection and studies have shown that the virosomal adjuvanted influenza vaccine is immunogenic and safe in different population groups including: the elderly, children and immunocompromised subjects. Currently available data suggest improved immunogenicity of the virosomal adjuvanted vaccine in the elderly and in subjects without protective antibody as compared to conventional vaccines.

Evidence of increased clinical protection of an MF59-adjuvant influenza vaccine compared to a non-adjuvant vaccine among elderly residents of long-term care facilities in Italy.

We evaluated whether the increased immunogenicity provided by an MF59-adjuvant influenza vaccine translates into increased protection among the elderly. Residents of 25 long-term care facilities received either the adjuvant or a non-adjuvant vaccine. The odds ratios (OR) of influenza-like illness were calculated for non-adjuvant vs. adjuvant vaccine recipients, also stratifying for chronic cardiovascular, respiratory, and renal diseases. The risk was higher for the non-adjuvant vaccine recipients and highest for those with respiratory disease (OR 2.27, 95% CI 1.09-4.82) and cardiovascular disease (OR 1.88; 95% CI 1.31-2.72). In this study the MF59-adjuvant vaccine provided superior clinical protection among the elderly, especially those with chronic diseases.

A study on the role of the family and other risk factors in HCV transmission.

BACKGROUND/AIMS: To understand the intrafamilial transmission and the existing risk factors related to HCV infection in subjects confirmed anti-HCV positive, their sexual partners and household contacts in Friuli, North-East Italy. METHODS: We enrolled all the subjects that were consecutively identified as HCV positive during routine laboratory testing in six health districts and their household contacts. From each subject we obtained a blood sample, demographic data and a medical history including the existence of risk factors for HCV. Antibodies to HCV were detected employing a commercially available second-generation enzyme immunoassay (EIA); positive serum specimens were retested using a second-generation recombinant immunoblot assay (RIBA-2). RESULTS: We recruited 743 subjects, 229 first subjects identified as HCV positive and 514 household contacts. There were no statistically significant differences in positivity among household contacts. Analysing intracouple transmission we found no significant differences by gender in couples both with and without parenteral risk factors. We found, both with univariate and multivariate analysis, as statistically significant risk factors in all the subjects: age older than 60, blood transfusions (particularly those performed before 1984), surgical procedures such as abortion and/or uterine curettage, history of HBV infection, intravenous drug use, and tattooing. CONCLUSIONS: Our results stress the low relevance of sexual transmission in the intrafamilial context, the importance of abortion and/or uterine curettage, the important role of blood transfusions in the past, a higher prevalence of HCV infection within a household of a HCV positive member compared to all other existing data in the area.

Hepatitis A infection: a seroepidemiological study in young adults in North-East Italy.

During the period from January to May 1994, the prevalence of antibodies to hepatitis A virus infection (anti-HAV) was tested by immunoenzyme assay in the serum samples of 620 apparently healthy subjects (81% males, 19% females), from 10 to 29 years old, resident in North-East Italy (Pordenone and surrounding district). The overall prevalence of anti-HAV was 3.7%. There was a significant lower prevalence in the group aged 10-19 than in the one aged 20-29 years (0.7% vs 6%; p < 0.001). Moreover, a significant sex difference was observed for the 20-29 year age group (p < 0.001). Among the various risk factors considered, family size and travelling abroad to endemic areas were significantly associated with HAV infection. Since a valid and effective vaccine against HAV infection has recently become available, anti-HAV vaccination campaigns can feasibly be programmed. However, different geographical regions present different epidemiological situations, so its use should be adapted to each region, with special attention to the cost-effectiveness of the immunisation programme. Our data suggest that in our region such vaccination could initially be proposed to high-risk subjects such as those travelling to endemic areas.