Validation of a double-color ELISpot assay of IFN-γ and IL-4 production in human peripheral blood mononuclear cells

The Enzyme-Linked ImmunoSpot (ELISpot) assay detects cytokines secreted during T cell-specific immune responses against pathogens. As this assay has acquired importance in the clinical setting, standard bioanalytical evaluation of this method is required. Here, we describe a formal bioanalytical validation of a double-color ELISpot assay for the evaluation of IFN-γ and IL-4 released by T helper 1 and T helper 2 cells, respectively. As recommended by international guidelines, the parameters assessed were: range and detection limits (limit of detection, LOD; upper and lower limit of quantification, ULOQ and LLOQ), Linearity, Relative Accuracy, Repeatability, Intermediate Precision, Specificity and Robustness. The results obtained in this validation study demonstrate that this assay meets the established acceptability criteria. ELISpot is therefore a reliable technique for measuring T cell-specific immune responses against various antigens of interest.

Waning intra-season vaccine effectiveness against influenza A(H3N2) underlines the need for more durable protection

BACKGROUND

The question of whether influenza vaccine effectiveness (VE) wanes over the winter season is still open and some contradictory findings have been reported. This study investigated the possible decline in protection provided by the available influenza vaccines.

RESEARCH DESIGN AND METHODS

An individual-level pooled analysis of six test-negative case-control studies conducted in Italy between the 2018/2019 and 2022/2023 seasons was performed. Multivariable logistic regression analyses were performed to estimate weekly change in the odds of testing positive for influenza 14 days after vaccination.

RESULTS

Of 6490 patients included, 1633 tested positive for influenza. Each week that had elapsed since vaccination was associated with an increase in the odds of testing positive for any influenza (4.9%; 95% CI: 2.0-8.0%) and for A(H3N2) (6.5%; 95% CI: 2.9-10.3%). This decline in VE was, however, significant only in children and older adults. A similar increase in the odds of testing positive was seen when the dataset was restricted to vaccinees only. Conversely, VE waning was less evident for A(H1N1)pdm09 or B strains.

CONCLUSIONS

Significant waning of VE, especially against influenza A(H3N2), may be one of the factors associated with suboptimal end-of-season VE. Next-generation vaccines should provide more durable protection against A(H3N2).

Trend of Correlations between Psychological Symptoms and Socioeconomic Inequalities among Italian Adolescents: Cross-Sectional Study from 2006 to 2018 in Tuscany Region

Adolescence is a critical moment in life; people become individuals, create new relationships, develop social skills and learn behaviours that they will use for the rest of their lives. During this phase, adolescents establish patterns of behaviour that can protect their health. This study aims to 1. assess the presence of psychological disorders in adolescents of both genders, 2. determine their relation to socio-economic differences based on the Family Affluence Scale (FAS), and 3. assess trends from 2006 to 2018. Data were collected from the Italian Health Behaviour in School-aged Children survey given to a representative sample of Tuscan adolescents aged 11-15 years. Participants (n. 12,550) filled out questionnaires to assess whether psychological symptoms such as feeling low, irritability, nervousness, or sleeping difficulties manifested weekly or more often over the past six months. For the study we utilized a cross-sectional survey method and linear regression to examine the association between psychological symptoms (dependent variable measured on an interval scale (0-16)), gender and FAS. We conducted similar analyses using logistic regressions for each of the four symptoms. An increase in psychological symptoms in both genders was revealed between 2006 and 2018, with a statistically significant presence in females: 0.29 (95% Confidence Interval [CI], 0.17 to 0.41), 1.43 (95% CI, 1.37 to 1.48) and 1.43 (95% CI, 1.34 to 1.52) in low-, medium- and high-affluence families, respectively; whereas males presented 0.14 (95% CI, 0.01 to 0.27), 0.71 (95% CI, 0.65 to 0.77) and 0.31 (95% CI, 0.22 to 0.39), respectively. The probability of a predictive episode of psychological symptoms (feeling low, irritability, nervousness, sleeping difficulties) occurring weekly, or more, often was greatly increased in females of all socioeconomic classes. These findings suggest that the increase in psychological disorders in adolescents should be considered a public health problem and further investigated through longitudinal studies and continuous monitoring of health trends.

Human Papillomavirus Epidemiology and Prevention: Is There Still a Gender Gap?

BACKGROUND AND AIM

Human papillomavirus (HPV) is sexually transmitted, one of the three most common sexually transmitted infections (STIs) in both males and females, and the most common viral STI. A crucial public health strategy to protect people against HPV is vaccination, which has shown its effectiveness in preventing HPV-related diseases. Presently, three types of vaccines are available (bivalent, quadrivalent, and nonvalent), and they all target the two most oncogenic virus genotypes (HPV 16 and 18). In recent years, the need to implement vaccination programmes that include all genders has been discussed in order to achieve herd immunity against HPV. To date, only a few countries have included young males in their vaccination programmes. Thus, our objective with this review is to provide an overview of the epidemiology of HPV and HPV prevention strategies and report the latest findings from the scientific literature.

Surveillance of Influenza and Other Airborne Transmission Viruses during the 2021/2022 Season in Hospitalized Subjects in Tuscany, Italy

Winter in the northern hemisphere is characterized by the circulation of influenza viruses, which cause seasonal epidemics, generally from October to April. Each influenza season has its own pattern, which differs from one year to the next in terms of the first influenza case notification, the period of highest incidence, and the predominant influenza virus subtypes. After the total absence of influenza viruses in the 2020/2021 season, cases of influenza were again recorded in the 2021/2022 season, although they remained below the seasonal average. Moreover, the co-circulation of the influenza virus and the SARS-CoV-2 pandemic virus was also reported. In the context of the DRIVE study, oropharyngeal swabs were collected from 129 Tuscan adults hospitalized for severe acute respiratory infection (SARI) and analyzed by means of real-time polymerase chain reaction (RT-PCR) for SARS-CoV-2 and 21 different airborne pathogens, including influenza viruses. In total, 55 subjects tested positive for COVID-19, 9 tested positive for influenza, and 3 tested positive for both SARS-CoV-2 and the A/H3N2 influenza virus. The co-circulation of different viruses in the population requires strengthened surveillance that is no longer restricted to the winter months. Indeed, constant, year-long monitoring of the trends of these viruses is needed, especially in at-risk groups and elderly people.

A serological investigation in Southern Italy: was SARS-CoV-2 circulating in late 2019?

In March 2020, the first pandemic caused by a coronavirus was declared by the World Health Organization. Italy was one of the first and most severely affected countries, particularly the northern part of the country. The latest evidence suggests that the virus could have been circulating, at least in Italy, before the first autochthonous SARS-COV-2 case was detected in February 2020. The present study aimed to investigate the presence of antibodies against SARS-CoV-2 in human serum samples collected in the last months of 2019 (September–December) in the Apulia region, Southern Italy. Eight of 455 samples tested proved positive on in-house receptor-binding-domain-based ELISA. Given the month of collection of the positive samples, these findings may indicate early circulation of SARS-CoV-2 in Apulia region in the autumn of 2019. However, it cannot be completely ruled out that the observed sero-reactivity could be an unknown antigen specificity in another virus to which subjects were exposed containing an epitope adventitiously cross-reactive with an epitope of SARS-CoV-2.

Relative effectiveness of the adjuvanted vs non-adjuvanted seasonal influenza vaccines against severe laboratory-confirmed influenza among hospitalized Italian older adults

OBJECTIVES

In this study, we aimed to investigate the relative vaccine effectiveness (rVE) of the MF59-adjuvanted trivalent (aTIV) and non-adjuvanted quadrivalent (QIVe) egg-based standard-dose vaccines against severe laboratory-confirmed influenza.

METHODS

This test-negative case-control study was conducted in a hospital setting during four recent Italian influenza seasons (from 2018/19 to 2021/22). The clinical outcome was severe acute respiratory infection (SARI) with laboratory confirmation diagnosed among subjects aged ≥65 years. rVE of aTIV versus QIVe was estimated through propensity score matching followed by logistic regression.

RESULTS

The influenza virus circulated to a significant extent only during the 2018/19 and 2019/20 seasons. The final population included 512 vaccinated older adults, of which 83 were cases and 429 were test-negative controls. aTIV and QIVe users differed substantially from the point of view of several baseline characteristics. The propensity score adjusted rVE of aTIV vs QIVe was 59.2% (95% CI: 14.6%, 80.5%), 54.7% (95% CI: -28.7%, 84.0%) and 56.9% (95% CI: -7.8%, 82.8%) against any influenza, A(H1N1)pdm09 and A(H3N2), respectively.

CONCLUSION

aTIV was more effective than QIVe in preventing laboratory-confirmed SARI. The benefits of aTIV may be obscured by confounding indication.

No evidence of SARS-CoV-2 in hospitalized patients with severe acute respiratory syndrome in five Italian hospitals from 1st November 2019 to 29th February 2020

BACKGROUND

On 9th January 2020, China CDC reported a novel coronavirus (later named SARS-CoV-2) as the causative agent of the coronavirus disease 2019 (COVID-19). Identifying the first appearance of virus is of epidemiological importance to tracking and mapping the spread of SARS-CoV-2 in a country. We therefore conducted a retrospective observational study to detect SARS-CoV-2 in oropharyngeal samples collected from hospitalized patients with a Severe Acute Respiratory Infection (SARI) enrolled in the DRIVE (Development of Robust and Innovative Vaccine Effectiveness) study in five Italian hospitals (CIRI-IT BIVE hospitals network) (1st November 2019 - 29th February 2020).

OBJECTIVES

To acquire new information on the real trend in SARS-CoV-2 infection during pandemic phase I and to determine the possible early appearance of the virus in Italy.

MATERIALS AND METHODS

Samples were tested for influenza [RT-PCR assay (A/H1N1, A/H3N2, B/Yam, B/Vic)] in accordance with the DRIVE study protocol. Subsequently, swabs underwent molecular testing for SARS-COV-2. [one-step real-time multiplex retro-transcription (RT) PCR].

RESULTS

In the 1683 samples collected, no evidence of SARS-CoV-2 was found. Moreover, 28.3% (477/1683) of swabs were positive for influenza viruses, the majority being type A (358 vs 119 type B). A/H3N2 was predominant among influenza A viruses (55%); among influenza B viruses, B/Victoria was prevalent. The highest influenza incidence rate was reported in patients aged 0-17 years (40.3%) followed by those aged 18-64 years (24.4%) and ≥65 years (14.8%).

CONCLUSIONS

In Italy, some studies have shown the early circulation of SARS-CoV-2 in northern regions, those most severely affected during phase I of the pandemic. In central and southern regions, by contrast no early circulation of the virus was registered. These results are in line with ours. These findings highlight the need to continue to carry out retrospective studies, in order to understand the epidemiology of the novel coronavirus, to better identify the clinical characteristics of COVID-19 in comparison with other acute respiratory illnesses (ARI), and to evaluate the real burden of COVID-19 on the healthcare system.

Surveillance for Severe Acute Respiratory Infections among Hospitalized Subjects from 2015/2016 to 2019/2020 Seasons in Tuscany, Italy

In Italy, the influenza season lasts from October until April of the following year. Influenza A and B viruses are the two viral types that cocirculate during seasonal epidemics and are the main causes of respiratory infections. We analyzed influenza A and B viruses in samples from hospitalized patients at Le Scotte University Hospital in Siena (Central Italy). From 2015 to 2020, 182 patients with Severe Acute Respiratory Infections were enrolled. Oropharyngeal swabs were collected from patients and tested by means of reverse transcriptase-polymerase chain reaction to identify influenza A(H3N2), A(H1N1)pdm09 and B. Epidemiological and virological surveillance remain an essential tool for monitoring circulating viruses and possible mismatches with seasonal vaccine strains, and provide information that can be used to improve the composition of influenza vaccines.

Moderate Vaccine Effectiveness against Severe Acute Respiratory Infection Caused by A(H1N1)pdm09 Influenza Virus and No Effectiveness against A(H3N2) Influenza Virus in the 2018/2019 Season in Italy

Every season, circulating influenza viruses change; therefore, vaccines must be reformulated each year. We aimed to estimate vaccine effectiveness (VE) against severe influenza infection for the 2018/19 season in Italy. We conducted a test-negative design case-control study at five Italian hospitals. We estimated influenza VE against severe acute respiratory infection (SARI) requiring hospitalisation overall, and by virus subtype, vaccine brand, and age. The 2018/19 season was characterised by A(H1N1)pmd09 and A(H3N2) influenza viruses. Vaccine coverage among <18 years recruited SARI cases was very low (3.2%). Seasonal vaccines were moderately effective against type A influenza overall (adjusted VE = 40.5%; 95% confidence interval (CI) = 18.7–56.4%) and subtype A(H1N1)pmd09 viruses (adjusted VE = 55%; 95% CI = 34.5–69.1%), but ineffective against subtype A(H3N2) viruses (adjusted VE = 2.5%; 95% CI = −50.0–36.7%). Both Fluad and Fluarix Tetra vaccines were effective against type A influenza overall and subtype A(H1N1)pdm09 viruses. VE appeared to be similar across age groups (0–64 years, ≥65 years). Seasonal influenza vaccines in the 2018/19 season were moderately effective in preventing SARI caused by A(H1N1)pdm09 influenza but ineffective against A(H3N2).

Influenza D Virus: Serological Evidence in the Italian Population from 2005 to 2017

Influenza D virus is a novel influenza virus, which was first isolated from an ailing swine in 2011 and later detected in cattle, suggesting that these animals may be a primary natural reservoir. To date, few studies have been performed on human samples and there is no conclusive evidence on the ability of the virus to infect humans. The aim of this serological study was to assess the prevalence of antibodies against influenza D virus in human serum samples collected in Italy from 2005 to 2017. Serum samples were analysed by haemagglutination inhibition and virus neutralization assays. The results showed that the prevalence of antibodies against the virus increased in the human population in Italy from 2005 to 2017, with a trend characterized by a sharp increase in some years, followed by a decline in subsequent years. The virus showed the ability to infect and elicit an immune response in humans. However, prevalence peaks in humans appear to follow epidemics in animals and not to persist in the human population.

Epidemiology and prevention of Human Papillomavirus

Human papillomavirus is the most common sexually transmitted infection, and skin-to-skin genital contact is sufficient for virus transmission. Cervical cancer is the second-most common cancer in women living in less developed regions, with an estimated 445,000 new cases in 2012 and 230,000 deaths every year. Until now, more than 200 types of HPV have been identified, and about 15 types (HPV-16, -18, -31, -33, -35, -39, -45, -51, -52, -56, -58, -59, -66, -68, -82) have been shown to cause cervical cancer because they are able to transform infected cells into malignant tumor cells. The bivalent vaccine containing the serotypes 16 and 18 and the quadrivalent vaccine containing the serotypes 16, 18, 6 and 11, have been used in Italy for many years. The European Medicines Agency authorized marketing of the Gardasil 9 vaccine in the European Union on June 2015. Today, Public Health targets the immunization of adolescents of both genders based on new and important scientific evidence for maximum protection from all HPV related pathologies directly preventable with vaccination.

How to assess the effectiveness of nasal influenza vaccines? Role and measurement of sIgA in mucosal secretions

Secretory IgAs (sIgA) constitute the principal isotype of antibodies present in nasal and mucosal secretions. They are secreted by plasma cells adjacent to the mucosal epithelial cells, the site where infection occurs, and are the main humoral mediator of mucosal immunity. Mucosally delivered vaccines, such as live attenuated influenza vaccine (LAIV), are able to mimic natural infection without causing disease or virus transmission and mainly elicit a local immune response. The measurement of sIgA concentrations in nasal swab/wash and saliva samples is therefore a valuable tool for evaluating their role in the effectiveness of such vaccines. Here, we describe two standardized assays (enzyme‐linked immunosorbent assay and microneutralization) available for the quantification of sIgA and discuss the advantages and limitations of their use.

Effectiveness of the trivalent MF59 adjuvated influenza vaccine in preventing hospitalization due to influenza B and A(H1N1)pdm09 viruses in the elderly in Italy, 2017 - 2018 season

Background: Evidence on influenza vaccine effectiveness (VE) in preventing mortality and morbidity in the elderly is weak. Our aim was to measure the VE against severe outcomes in the elderly. Methods: We conducted a multicentre hospital-based test-negative design (TND) case-control study, during the 2017/18 season, in four Italian hospitals. The study population included individuals aged ≥65 years hospitalized with Severe Acute Respiratory Infections (SARI). Patients were classified as cases and controls based on the results of the PCR influenza testing. We estimated VE by virus subtypes and specific VE for the trivalent adjuvanted vaccine (TIVadj). Results: 502 patients with SARI were enrolled: 118 (23.5%) tested positive (cases) and 384 (76.5%) tested negative (controls) for influenza. The adjusted VE of 48.5% for all vaccines was comparable to the adjusted VE for the TIVadj vaccine (48.3%). Adjusted VE for the TIVadj vaccine was 67.5% for A(H1N1)pdm09 and 44.5% for B viruses. Conclusion: We show a moderate adjusted VE of the TIVadj against all viruses, a good adjusted VE against A(H1N1)pdm09 strains and a moderate adjusted VE against B strains, despite a mismatch between the B circulating lineage and the lineage included in the vaccine. This is likely due to the cross-protection among B strains induced by the TIVadj in elderly patients.

Medicine use and recurrent complaints among 15-years-old adolescents in Tuscany

BACKGROUND

The use of medicines to treat common complaints, such as headache, stomachache, difficulty in getting to sleep and nervousness, is widespread among adolescents, and is increasing. The aim of this survey was to estimate the prevalence of recurrent specific complaints among 15-year-old adolescents in Tuscany over three years (2006, 2010 and 2014) and that of medicine use to treat these complaints among boys and girls.

METHODS

The present study is based on data from the Tuscan HBSC studies at three time points (2006, 2010 and 2014), which involved 2830 adolescents, aged 15 years old (1395 boys and 1435 girls).

RESULTS

Overall, the data confirm that adolescents who suffer from recurrent complaints are more likely to use medicines. The prevalence rates of all complaints were higher in girls than in boys in the three years considered. Over the whole period, headache, stomachache and difficulty in getting to sleep increased in girls, while boys displayed significant decrease in nervousness and stomachache.

CONCLUSION

Our findings underline the fact that the use of medicines in adolescence is a public health concern and constitutes an emerging issue that needs greater attention and investigation on the part of scientific research.

[Trends of overweight and obesity prevalence among schoolchildren in Tuscany Region (Central Italy), period 2002-2016]

OBJECTIVES

to examine the prevalence and time trends in childhood overweight (including obesity) and obesity among children dwelling in Tuscany Region (Central Italy) in the period 2002-2016.

DESIGN

cross-sectional study at seven points (Tuscan Nutritional Surveillance System conducted in the years 2002, 2006, 2008, 2010, 2012, 2014, and 2016); height and weight of the subjects are directly measured by trained staff; body mass index was assessed by means of the International Obesity Task Force and of the World Health Organization cut-offs.

SETTING AND PARTICIPANTS

representative sample of children dwelling in Tuscany Region (No. 10,155) aged between 8 and 9 years (5,258 boys and 4,897 girls).

RESULTS

regarding the estimation of the absolute prevalence level of childhood overweight, a discrepancy was observed between the two criteria. In all surveys, more boys than girls were overweight (or obese). Trend analysis showed a significant decrease in the prevalence of overweight (including obesity) and obesity in Tuscan children in the period 2002-2016 (32.0% vs. 28.1%; p <0.001) and of 10.0% vs. 5.9% (p <0.001) for obesity.

CONCLUSIONS

the present study is the first report from an Italian region showing a significant decrease in childhood obesity and overweight in the last 14 years. This reduction is probably a result of regional and local actions that were performed in many areas of society. However, efforts should be made to further reduce prevalence of childhood obesity and overweight.

"OKKIO alla salute 2014" results from the Tuscan sample

BACKGROUND

The prevalence of overweight and obesity among children is rapidly increasing in many countries. For this reason we decided to investigate the eating habits of 8-9 years old Tuscany children, by paying attention to the frequency of their meals per day and to their food choices, also in relation to children's Body Mass Index (BMI) classes. In addition, we considered some environmental factors that could affect children eating behaviors, such as parents' BMI.

METHODS

Data from the 2014 Tuscany nutritional surveillance system (part of the national periodical survey) and collected from children, parents and teachers, have been linked to study of children's eating habits. Logistic regression analyses were used to investigate the association between incorrect dietary habits and the potential predictors of overweight and obesity.

RESULTS

More than half of the 2,163 children (68.64% overall, 67.61% females, 69.56% males) reported to have eaten an appropriate breakfast in the morning, while 5.9% skipped breakfast and only 33.5% of children ate an appropriate mid-morning snack. Logistic regression showed that having breakfast and especially an adequate breakfast are protective factors against obesity (OR 0.57, p<0.01; OR 0.84; p=0.03 respectively).

CONCLUSION

In Tuscany Region, unhealthy dietary habits are common among children. The identified deficiencies may be a harbinger of future public health problems.

Immunogenicity and Safety of the New Inactivated Quadrivalent Influenza Vaccine Vaxigrip Tetra: Preliminary Results in Children ≥6 Months and Older Adults

Since the mid-1980s, two lineages of influenza B viruses have been distinguished. These can co-circulate, limiting the protection provided by inactivated trivalent influenza vaccines (TIVs). This has prompted efforts to formulate quadrivalent influenza vaccines (QIVs), to enhance protection against circulating influenza B viruses. This review describes the results obtained from seven phase III clinical trials evaluating the immunogenicity, safety, and lot-to-lot consistency of a new quadrivalent split-virion influenza vaccine (Vaxigrip Tetra®) formulated by adding a second B strain to the already licensed TIV. Since Vaxigrip Tetra was developed by means of a manufacturing process strictly related to that used for TIV, the data on the safety profile of TIV are considered supportive of that of Vaxigrip Tetra. The safety and immunogenicity of Vaxigrip Tetra were similar to those of the corresponding licensed TIV. Moreover, the new vaccine elicits a superior immune response towards the additional strain, without affecting immunogenicity towards the other three strains. Vaxigrip Tetra is well tolerated, has aroused no safety concerns, and is recommended for the active immunization of individuals aged ≥6 months. In addition, preliminary data confirm its immunogenicity and safety even in children aged 6-35 months and its immunogenicity in older subjects (aged 66-80 years).

Egg-Independent Influenza Vaccines and Vaccine Candidates

Vaccination remains the principal way to control seasonal infections and is the most effective method of reducing influenza-associated morbidity and mortality. Since the 1940s, the main method of producing influenza vaccines has been an egg-based production process. However, in the event of a pandemic, this method has a significant limitation, as the time lag from strain isolation to final dose formulation and validation is six months. Indeed, production in eggs is a relatively slow process and production yields are both unpredictable and highly variable from strain to strain. In particular, if the next influenza pandemic were to arise from an avian influenza virus, and thus reduce the egg-laying hen population, there would be a shortage of embryonated eggs available for vaccine manufacturing. Although the production of egg-derived vaccines will continue, new technological developments have generated a cell-culture-based influenza vaccine and other more recent platforms, such as synthetic influenza vaccines.

Cell culture-derived influenza vaccines from Vero cells: a new horizon for vaccine production

In the 20th century, three influenza pandemics killed approximately 100 million people. The traditional method of influenza vaccine manufacturing is based on using chicken eggs. However, the necessity of the availability of millions of fertile eggs in the event of a pandemic has led research to focus on the development of cell culture-derived vaccines, which offer shorter lead-in times and greater flexibility of production. So far, the cell substrates being evaluated and in use include Vero, Madin-Darby canine kidney, PER.C6 and insect cells. However, Vero cells are the most widely accepted among others. This review introduces briefly the concepts of advanced cell culture-derived influenza vaccine production and highlights the advantages of these vaccines in terms of efficiency, speed and immunogenicity based on the clinical data obtained from different studies.

Hepatitis A seroprevalence in Tuscany, Italy

Information regarding the current seroprevalence of hepatitis A virus (HAV) is useful for the control of HAV infections. The objective of our study was to evaluate the prevalence of anti-HAV antibodies among children (1-5 years old) and young adults (15-20 years old) in Tuscany, in central Italy. A total of 565 sera were collected in three years 1992, 1998 and 2004, equally distributed between the two age groups. The overal proportion of those that tested positive for anti-HAV antibodies was 8.3%. The proportion of immune children (1-5 years old) statistically significantly increased over the years. The percentage of immune subjects among 15-20-year-old young adults varied over the years, not showing a significant statistical trend, nevertheless our findings indicate that in a low endemicity area, adolescents and young adults are becoming increasingly susceptible to HAV infection. On-going monitoring of immunity to HAV is necessary for detecting trends over time.

Hepatitis A seroprevalence in Tuscany, Italy

Information regarding the current seroprevalence of hepatitis A virus (HAV) is useful for the control of HAV infections. The objective of our study was to evaluate the prevalence of anti-HAV antibodies among children (1-5 years old) and young adults (15-20 years old) in Tuscany, in central Italy. A total of 565 sera were collected in three years 1992, 1998 and 2004, equally distributed between the two age groups. The overal proportion of those that tested positive for anti-HAV antibodies was 8.3%. The proportion of immune children (1-5 years old) statistically significantly increased over the years. The percentage of immune subjects among 15-20-year-old young adults varied over the years, not showing a significant statistical trend, nevertheless our findings indicate that in a low endemicity area, adolescents and young adults are becoming increasingly susceptible to HAV infection. On-going monitoring of immunity to HAV is necessary for detecting trends over time.

Susceptibility to varicella in childbearing age women, Central Italy: is there a need for vaccinating this population group?

We conducted a cross-sectional seroprevalence study of varicella-zoster virus (VZV) antibodies in childbearing age women aged 17-42 years. Sera were collected in Central Italy in years 2001-2002 and were tested by a commercial VZV IgG enzyme immunoassay. Overall VZV seroprevalence was 80.9% and it showed a significant increase by age, confirming a considerable circulation of VZV also in the older age groups not commonly considered at high risk. This study further supports the importance of vaccinating susceptible adolescents and women of childbearing age in order to reduce both maternal and foetal complications associated with varicella in pregnancy.

Prevalence of antibodies to Vaccinia virus after smallpox vaccination in Italy

Decades after smallpox was eradicated and vaccination discontinued, the level of residual immunity in today's population is largely unknown. This study describes an epidemiological assessment in Italians of antibodies against the intracellular mature virus (IMV) and extracellular envelope virus (EEV) forms of Vaccinia virus. Serum samples (n=642) were taken in 1993 and 2003 from people between 11 and 102 years old. Most citizens >27 years old were positive for antibodies to IMV and EEV. These antibodies were long-lasting and similar titres were present in citizens between 30 and 100 years old. Serum samples from 1993 and 2003 displayed very similar EEV- and IMV-specific antibody titres. By using these data and demographic considerations, it was predicted that, in 2003, 46 % of the Italian population were positive for both IMV and EEV, 42 % were negative for both and 12 % were positive for one antigen.