Donatella Panatto

Neisseria meningitidis B vaccines

Invasive infections caused by Neisseria meningitidis are a serious public health problem worldwide and have a heavy economic impact. The incidence of invasive disease due to Neisseria meningitidis is highly variable according to geographical area and serogroup distribution. Since the introduction of vaccination programs with conjugated vaccine C in children and adolescents, most cases of invasive meningococcal disease in developed countries have been caused by meningococcus B. It is important to underline that invasive meningococcal disease will not be controlled until safe and effective vaccines for meningococcal B are available and widely used. The aims of this article are to describe the most recent developments in meningococcal B vaccines and to discuss how these vaccines can contribute to containing meningococcal disease.

Epidemiology of tick-borne encephalitis (TBE) in Europe and its prevention by available vaccines

Tick-borne Encephalitis (TBE), which is caused by a Flavivirus, is the most common tick-transmitted disease in Central and Eastern Europe and Russia. Today, TBE is endemic in 27 European countries, and has become an international public health problem. The epidemiology of TBE is changing owing to various factors, such as improvements in diagnosis and case reporting, increased recreational activities in areas populated by ticks, and changes in climatic conditions affecting tick habitats. Vaccination remains the most effective protective measure against TBE for people living in risk zones, occupationally exposed subjects and travelers to endemic areas. The vaccines currently in use are FSME-Immun®, Encepur®, EnceVir® and TBE vaccine Moscow®. The numerous studies performed on the efficacy and safety of these vaccines have shown a high level of immunogenicity and an excellent safety profile. Several studies have also shown a high level of cross-protection among strains belonging to different subtypes. In the present paper we attempted to describe the continuously changing epidemiology of TBE in European States and to overview clinical development of available vaccines paying particular attention on cross-protection elicited by the vaccines.

Clinical and socioeconomic impact of seasonal and pandemic influenza in adults and the elderly

Influenza epidemics and pandemics carry a heavy socioeconomic burden. Hospitalization and treatment are more often necessary in high-risk patients, such as the elderly. However, the impact of influenza is not negligible even in adults, mainly because of lost productivity. The World Health Organization estimates that seasonal influenza causes 250,000–500,000 deaths worldwide each year; however, mortality may be very high in pandemic periods. Many estimates of the costs of seasonal influenza have been made in various socioeconomic contexts. For instance, among the adult population in Italy, a cost of €940.39 per case has been estimated. In the US, the average annual influenza burden in 18–49-y-old adults without underlying medical conditions is judged to include approximately 32,000 hospitalizations and 680 deaths. Estimating the influenza burden is a useful aid to determining the best influenza vaccination strategy and preventive and clinical treatments.

Meningococcal glycoconjugate vaccines

Neisseria meningitidis is a major cause of invasive bacterial infections worldwide. For this reason, efforts to control the disease have been directed at optimizing meningococcal vaccines and implementing appropriate vaccination policies. In the past, plain polysaccharide vaccines containing purified capsular polysaccharides A, C, Y and W135 were developed, but failed to protect infants, who are at greatest risk. Experience with the conjugate Haemophilus vaccine suggested that this approach might well empower meningococcal vaccines. Thus, a very efficacious vaccine against serogroup C Neisseria meningitis was optimized and has been widely used in developed nations since 1999. On the basis of epidemiological changes in the circulation of pathogenic serogroups in the United States, a quadrivalent conjugate vaccine against A, C, Y and W135 serogroups (Menactra™) has been developed and was approved by the U.S. FDA (Food and Drug Administration) in 2005. Recently, another tetravalent conjugate meningococcal vaccine (Menveo™) has been licensed and made available in the United States of America and in the European Union. Finally, in response to large epidemics caused by serogroup A meningococcus in Africa, a new, safe, immunogenic and affordable vaccine has been developed. This review highlights the evolution of conjugate meningococcal vaccines in general and discusses how this kind of vaccine can contribute to preventing meningococcal disease.

An overview on the implementation of HPV vaccination in Europe

The discovery that the Human PapillomaVirus (HPV) is the necessary cause of cervical cancer has led to the development of prophylactic vaccines. Cervical cancer is the second most common cause of death from cancer among young women in Europe: mortality is still high, despite its important reduction due to screening programs for early detection. Besides cervical cancer, HPV is responsible for a significant proportion of other anogenital cancers and an increasing number of oropharyngeal cancers, representing together an at least equal burden compared to cervical cancer. HPV is also responsible for conditions such as condyloma acuminata (genital warts) and recurrent respiratory papillomatosis. Organized vaccination programs against HPV have the potential to prevent about 70% of cervical cancers and the vast majority of the other HPV-related conditions. Recommendations for HPV vaccination of at least one cohort of females have been issued in nearly all western European countries, and national/regional publicly funded vaccination programs have been introduced in most of them. Different approaches have been chosen for the implementation of HPV vaccination, based on the organization of each countrys health care system. A brief outline of these programs in Europe is presented. As for all preventive public health interventions, high coverage of the target population with HPV vaccines pre-exposure is essential to achieve maximum reduction of cases: therefore, in order to obtain the maximum and most equitable coverage and future benefit, programs targeting adolescents before exposure to HPV should be preferred and population-based. Catch-up programs should also be implemented wherever possible, in order to deliver more and even earlier benefits, and effective communication strategies need to be adopted.

Effectiveness of MF59-adjuvanted seasonal influenza vaccine in the elderly: A systematic review and meta-analysis.

BACKGROUND In the elderly, traditional influenza inactivated vaccines are often only modestly immunogenic, owing to immunosenescence. Given that adjuvantation is a means of enhancing the immune response, the trivalent inactivated vaccine adjuvanted with MF59 (MF59-TIV) was specifically designed to overcome this problem. Considering that, for ethical reasons, the absolute effectiveness of an influenza vaccine in the elderly cannot be demonstrated in placebo-controlled studies, the present study aimed to assess the effectiveness of MF59-TIV in preventing influenza-related outcomes in the elderly. METHODS We conducted a systematic review of observational studies aimed at evaluating the effectiveness of MF59-TIV against influenza-related outcomes. Results of single studies were pooled whenever possible. RESULTS Of the 1993 papers screened, 11 (6 case-control, 3 cohort and 2 prospective case-control) studies were identified. Hospitalization due to pneumonia/influenza and laboratory-confirmed influenza were reported in more than one study, while other outcomes (influenza-like illness, cardio- and cerebrovascular accidents) were investigated only by one study each. Pooled analysis of four case-control studies showed an adjusted MF59-TIV effectiveness of 51% (95% CI: 39-61%) against hospitalizations for pneumonia/influenza among community-dwelling seniors. Pooled results of the adjusted vaccine effectiveness against laboratory-confirmed influenza were also high (60.1%), although the 95% CI passed through zero (-1.3 to 84.3%). Other single community-based studies showed very high effectiveness of MF59-TIV in preventing hospitalizations for acute coronary [87% (95% CI: 35-97%)] and cerebrovascular [93% (95% CI: 52-99%)] events. MF59-TIV proved highly effective [94% (95% CI: 47-100%] in reducing influenza-like illness among institutionalized elderly. Furthermore, MF59-TIV displayed greater efficacy than non-adjuvanted vaccines in preventing hospitalizations due to pneumonia/influenza [adjusted risk ratio 0.75 (95% CI: 0.57-0.98)] and laboratory-confirmed influenza [adjusted odds ratio 0.37 (0.14-0.96)]. CONCLUSIONS Our results suggest that MF59-TIV is effective in reducing several influenza-related outcomes among the elderly, especially hospitalizations due to influenza-related complications.

Assessing Ebola-related web search behaviour: insights and implications from an analytical study of Google Trends-based query volumes

BackgroundThe 2014 Ebola epidemic in West Africa has attracted public interest worldwide, leading to millions of Ebola-related Internet searches being performed during the period of the epidemic. This study aimed to evaluate and interpret Google search queries for terms related to the Ebola outbreak both at the global level and in all countries where primary cases of Ebola occurred. The study also endeavoured to look at the correlation between the number of overall and weekly web searches and the number of overall and weekly new cases of Ebola.MethodsGoogle Trends (GT) was used to explore Internet activity related to Ebola. The study period was from 29 December 2013 to 14 June 2015. Pearson’s correlation was performed to correlate Ebola-related relative search volumes (RSVs) with the number of weekly and overall Ebola cases. Multivariate regression was performed using Ebola-related RSV as a dependent variable, and the overall number of Ebola cases and the Human Development Index were used as predictor variables.ResultsThe greatest RSV was registered in the three West African countries mainly affected by the Ebola epidemic. The queries varied in the different countries. Both quantitative and qualitative differences between the affected African countries and other Western countries with primary cases were noted, in relation to the different flux volumes and different time courses. In the affected African countries, web query search volumes were mostly concentrated in the capital areas. However, in Western countries, web queries were uniformly distributed over the national territory. In terms of the three countries mainly affected by the Ebola epidemic, the correlation between the number of new weekly cases of Ebola and the weekly GT index varied from weak to moderate. The correlation between the number of Ebola cases registered in all countries during the study period and the GT index was very high.ConclusionGoogle Trends showed a coarse-grained nature, strongly correlating with global epidemiological data, but was weaker at country level, as it was prone to distortions induced by unbalanced media coverage and the digital divide. Global and local health agencies could usefully exploit GT data to identify disease-related information needs and plan proper communication strategies, particularly in the case of health-threatening events.

Sexual behaviour and risk factors for the acquisition of human papillomavirus infections in young people in Italy: suggestions for future vaccination policies

BackgroundHuman Papillomavirus (HPV) is the most common sexually transmitted infection. The main risk factors correlated with HPV infection are: early sexual debut, the number of partners, frequency and type of sexual contact and partner’s sexual histories.We surveyed sexual habits among young people in order to provide information that might orient decision-makers in adopting HPV multi-cohort vaccination policies.MethodsWe administered a questionnaire to students (14–24 years old) in five Italian cities.Results7298 questionnaires were analyzed (4962 females and 2336 males); 55.3% of females (95% CI 53.9–56.7) and 52.5% of males (95% CI 50.5–54.5) reported regular sexual activity. The mean age at sexual debut was 15.7 ± 1.6 and 15.6 ± 1.6 for females and males, respectively, and the median age was 16 for both sexes.With regard to contraceptive use during the last year, 63.6% of males and 62.8% of females responded affirmatively; 42.6% of males and 42.8% of females used condoms.ConclusionThe results reveal precocious sexual activity among respondents, with the mean age at first intercourse declining as age decreases. Condom use proved to be scant. Considering lifestyle-related risk factors, males appear to have a higher probability of acquiring HPV infection than females.These data support the importance of promoting multi-cohort HPV vaccination strategies for females up to 25 years of age. It is essential to improve vaccination coverage through different broad-spectrum strategies, including campaigns to increase awareness of sexually transmitted diseases and their prevention.

The “healthy immigrant” effect: does it exist in Europe today?

Several studies, carried out mainly in the United States and Canada, have suggested that recent immigrants are generally healthier than native-born populations in spite of the fact that they frequently have a lower socioeconomic status and less access to healthcare services. This “epidemiological paradox” has been called the “healthy immigrant” effect and is usually attributed to a self-selection process prior to migration, “cultural buffering” and official health screening and employability in receiving countries. In this paper, we have evaluated the European scientific research into the existence of the “healthy immigrant” effect.

Burden of the 1999-2008 seasonal influenza epidemics in Italy: comparison with the H1N1v (A/California/07/09) pandemic.

Despite preventive efforts, seasonal influenza epidemics are responsible for substantial morbidity and mortality every year worldwide, including developed countries. The A/H1N1v pandemic imposed a considerable healthcare and economic burden. In order to obtain an accurate estimate of the economic burden of influenza, and hence to guide policy-makers effectively, systematic studies are necessary. To this end, data from epidemiological surveillance are essential. To estimate the impact of the 1999-2008 seasonal influenza epidemics and the H1N1v pandemic, we analyzed data from the Italian Influenza Surveillance System (CIRINET). In the period 1999-2008, the Italian surveillance network consisted of sentinel general practitioners and pediatricians, who reported cases of Influenza-Like Illness (ILI) and Acute Respiratory Infections (ARI) observed during their clinical practice from mid-October to late April each year; reports were sent to the Center for Research on Influenza and other Viral Infections (CIRI-IV). CIRI-IV receives data from 9 of the 20 Italian Regions: Liguria, Abruzzo, Calabria, Friuli Venezia Giulia, Lombardy, Puglia, Sicily, Tuscany and Umbria. Previous estimates of influenza case costs were used in economic evaluations. Clinical-epidemiological and Virological surveillance of the seasonal epidemics from 1999-2008 showed that the highest epidemic period was 2004-2005, when a new variant of the H3N2 influenza virus subtype emerged (A/California/07/04). Indeed, the highest peak of morbidity in the decade occurred in February 2005 (12.6 per 1,000 inhabitants). In 1999-2008, H1N1 subtype strains circulated, and co-circulated with strains belonging to the H3N2 subtype and B type. Regarding B viruses in 2001-02, viruses belonged to the B/Victoria/02/07 lineage re-emerged, and in subsequent years co-circulated with viruses belonging to the B/Yamagata/lineage. The estimated costs of seasonal epidemics from 1999-2008 in Italy ranged from €15 to €20 billion, and the costs of the H1N1v pandemic ranged from €1.3 to €2.3 billion. This Italian study yields interesting conclusions: the results of Influenza surveillance in several developed countries vary markedly; influenza imposes a considerable social, healthcare and economic burden; most cases that occurred during the pandemic involved subjects under 14 years of age, and, although the clinical course of H1N1v influenza was usually mild, the related economic burden was heavy.