Distribution of invasive meningococcal B disease in Italian pediatric population: implications for vaccination timing

Available evidence on the co-administration of the four-component meningococcal B vaccine (4CMenB) with three vaccines at the same visit among pediatric individuals

Vaccine co-administration is a useful strategy for improving vaccine coverage and adherence. In Italy, an update to the national immunization program (NIP) in 2023 included recommendations for co-administration of pediatric vaccines, including the four-component vaccine for meningococcus B (4CMenB), pneumococcal conjugate vaccine (PCV), hexavalent vaccines, and oral rotavirus vaccines. Safety is a major concern when considering vaccine co-administration; therefore, a literature review of the available evidence on 4CMenB co-administration with PCV, hexavalent/pentavalent, and rotavirus vaccines was performed. Of 763 publications screened, two studies were reviewed that reported safety data on 4CMenB co-administration with PCV, hexavalent/pentavalent, and rotavirus vaccines in infants aged 0-24 months. Overall, these studies supported that there were no significant safety signals when co-administering 4CMenB with PCV, hexavalent/pentavalent, and rotavirus vaccines, compared with individual vaccination. This review provides key insights for healthcare professionals on the tolerability of co-administering 4CMenB with routine vaccines.

Insights and expectations of healthcare professionals on the implementation of the updated pediatric regional immunization Calendar in Calabria, Italy

The Regional Immunization Calendar in Calabria, a region of Italy, was updated in 2022, introducing optional co-administration of three injectable vaccines, with one oral vaccine, at 3 and 5 months old, and three injectable vaccines at 13-14 months old. In this project, the opinions and expectations of healthcare professionals (HCPs) in Calabria were investigated, with respect to the updated recommended practices. An 11-question survey was developed, which addressed concepts and topics related to immunization calendar implementation. Focus group discussions were also organized to provide further insight on the survey findings. A total of 132 HCPs completed the survey (86 public health providers [PHs] and 46 family pediatricians [FPs]). Overall, ≥50% of respondents agreed that vaccine co-administration would be advantageous for public health by reducing the number of vaccination sessions required. Most PHs and FPs agreed that dissemination of available safety data on vaccine co-administration is a necessary action to facilitate effective implementation of the strategy into clinical practice. The importance of safety data related to vaccine co-administration was supported further by discussions held in PH and FP focus groups. Overall, these findings demonstrate support from HCPs in Calabria for vaccine co-administration, and highlight key activities needed for successful uptake.

Four-Component Recombinant Protein-Based Vaccine Effectiveness Against Serogroup B Meningococcal Disease in Italy

Importance

Population-based data on the 4-component recombinant protein-based (4CMenB) vaccine effectiveness and reduction in incidence rate ratios (IRRs) are continuously needed to assess vaccine performance in the prevention of serogroup B invasive meningococcal disease (IMD).

Objective

To assess the effectiveness and reduction in IRRs associated with the 4CMenB vaccine in the pediatric population in 6 regions in Italy.

Design, Setting, and Participants

This retrospective cohort screening study and case-control study included data from children aged younger than 6 years in 6 highly populated Italian regions from January 1, 2006, to January 1, 2020. Participants included children younger than 6 years diagnosed with serogroup B IMD without predisposing factors. Data were collected from regional surveillance and vaccination registries and were analyzed from September 2021 to January 2022.

Exposures

Routine 4CMenB vaccination, per regional vaccination programs.

Main Outcomes and Measures

The main outcome was the effectiveness of the 4CMenB vaccine in the prevention of serogroup B IMD in the population of children aged younger than 6 years in 6 Italian regions. The percentages of vaccine effectiveness (VE) were obtained through the concomitant use of a screening method and a case-control study. Secondary outcomes were the comparison of effectiveness results obtained using the 2 different computational methods, the description of serogroup B IMD incidence rates, and reduction in IRRs before and after 4CMenB introduction, as a proxy for vaccine impact.

Results

The cohort screening study included a resident population of 587 561 children younger than 6 years in 3 regions with similar surveillance protocols, and the matched-case controls study assessed a resident population of 1 080 620 children younger than 6 years in 6 regions. Analyses found that 4CMenB VE in fully immunized children was 94.9% (95% CI, 83.1%-98.4%) using the screening method and 91.7% (95% CI, 24.4%-98.6%) using the case-control method. Overall reduction in IRR was 50%, reaching 70% in regions with early-start vaccination schedules. The case-control method involving 6 highly-populated Italian regions included 26 cases and 52 controls and found an estimated VE of 92.4% (95% CI, 67.6%-97.9%) in children old enough for the first vaccine dose and 95.6% (95% CI, 71.7%-99.1%) in fully immunized children. VE was more than 90% for partially immunized children. Even in regions where the first dose was administered at age 2 months, almost 20% of unvaccinated cases were among infants too young to receive the first 4CMenB dose.

Conclusions and Relevance

This screening cohort study and matched case-controls study found high effectiveness of 4CMenB vaccination and greater reduction in IRR for early-start vaccination schedules in preventing invasive serogroup B meningococcal disease. The high proportion of children too young to be vaccinated among unvaccinated cases suggests that starting the vaccination even earlier may prevent more cases. Screening and case-control methods provided similar estimates of VE: either method may be used in different study settings, but concomitant use can provide more robust estimates.

Italian immunization calendar implementation: Time to optimize number of vaccination appointments?

In the Italian vaccination schedule, at least six vaccination appointments are scheduled in the first year of life. This implies more discomfort for both the patient and the parents. This was particularly evident during the COVID-19 pandemic, during which several appointments were missed. A UK experience with three injectable vaccines and an oral one co-administered at the same appointment (4-in-1) at 2 and 4 months of age showed interesting results. The vaccination coverage was high, consistent with previous practice, and no relevant increase in adverse events was reported. Translating the UK experience into the Italian context would not be immediate, due to several organizational and social issues. Nevertheless, this option warrants some further considerations, which are discussed in this manuscript.

Meningococcal Disease in Pediatric Age: A Focus on Epidemiology and Prevention

Meningococcal disease is caused by Neisseria meningitidis; 13 serogroups have been identified and differentiated from each other through their capsular polysaccharide. Serotypes A, B, C, W, X, and Y are responsible for nearly all infections worldwide. The most common clinical manifestations are meningitis and invasive meningococcal disease, both characterized by high mortality and long-term sequelae. The infection rate is higher in children younger than 1 year and in adolescents, who are frequently asymptomatic carriers. Vaccination is the most effective method of preventing infection and transmission. Currently, both monovalent meningococcal vaccines (against A, B, and C serotypes) and quadrivalent meningococcal vaccines (against serogroups ACYW) are available and recommended according to local epidemiology. The purpose of this article is to describe the meningococcal vaccines and to identify instruments that are useful for reducing transmission and implementing the vaccination coverage. This aim could be reached by switching from the monovalent to the quadrivalent vaccine in the first year of life, increasing vaccine promotion against ACYW serotypes among adolescents, and extending the free offer of the anti-meningococcal B vaccine to teens, co-administering it with others proposed in the same age group. Greater awareness of the severity of the disease and increased health education through web and social networks could represent the best strategies for promoting adhesion and active participation in the vaccination campaign. Finally, the development of a licensed universal meningococcal vaccine should be another important objective.

Real-time polymerase chain reaction on filter paper spotted samples: a gateway to molecular diagnosis of invasive bacterial diseases for rural areas in low-income countries

BACKGROUND

Bacterial culture is the gold standard for the diagnosis of invasive bacterial diseases (IBDs) but molecular methods are more specific and sensitive. Fresh liquid samples (FLSs) show patent limitations for shipping and storage. We aimed to evaluate the sensitivity and specificity of real-time polymerase chain reaction (PCR) performed on dried sample spots (DSSs) obtained from different biological fluids compared with real-time PCR or culture performed on FLSs.

METHODS

FLSs positive for Streptococcus pneumoniae, Neisseria meningitidis, Haemophilus influenzae, Escherichia coli, Streptococcus pyogenes, Staphylococcus aureus, Bordetella pertussis and/or Pseudomonas aeruginosa were spotted on filter paper. Real-time PCR was performed on both FLSs and DSSs and results were compared. The stability of the DSS results over time was evaluated.

RESULTS

Real-time PCR performed on 114 DSSs showed a specificity of 99.1% and a sensitivity of 91.2% for IBD diagnosis. A positive correlation was found between FLS cycle threshold (Ct) and DSS Ct (r=0.84; r2=0.71) with the Pearson statistical test and Bland-Altman analysis showing that 95% of the specimens were within agreeable limits. Although we observed a trend towards signal reduction over time in the DSSs, there was no statistical evidence of an increase in Ct values. Real-time PCR on DSSs was 2.2 times more sensitive than culture.

CONCLUSIONS

Real-time PCR applied to DSSs may be a useful approach in different situations, such as IBD diagnosis, both for rural areas of low-income countries and family practitioners in various settings.

Economic evaluation of meningococcal serogroup B (MenB) vaccines: A systematic review

BACKGROUND

Meningococcal serogroup B (MenB) has emerged as the leading cause of invasive meningococcal disease (IMD) in several countries following the release of effective vaccines against serogroups A, C, W, and Y. In 2013, however, the first multicomponent MenB vaccine (Bexsero®) was licensed in Europe.

AIM

To review the evidence on the cost-effectiveness of vaccination against MenB.

METHODS

Searches were performed in MEDLINE, EMBASE, Web of Science, NHS EED, Econlit, Tufts CEA registry, and HTA. Three reviewers independently screened and selected studies. Using a narrative synthesis, studies were categorized by vaccination strategies. The quality of included studies was assessed using the Comparative Health Economics Evaluation Reporting Standards (CHEERS) checklist.

RESULTS

13 studies were included. Ten studies were conducted in the European region and three in the Americas. None of the vaccination strategies were considered cost-effective. Including herd effects improved value for money for MenB vaccines. Routine infant vaccination was the most effective short-term strategy, however, adolescent strategies offered the best value for money. Without herd immunity, routine infant vaccination had the lowest incremental cost-effectiveness ratio estimates.

CONCLUSION

Routine MenB vaccination does not offer substantial value for money, mainly due to high vaccine costs and low disease incidence.

Molecular typing of group B Neisseria meningitidis'subcapsular antigens directly on biological samples demonstrates epidemiological congruence between culture-positive and -negative cases: A surveillance study of invasive disease over a 13-year period

BACKGROUND

Surveillance of serogroup B Neisseria meningitidis (MenB) subcapsular antigen variant distribution in invasive disease (IMD) is fundamental for multicomponent vaccine coverage prediction. IMD incidence in Tuscany in 2018 was 0.37/100,000 inhabitants, with MenB representing 57% of cases. More than 50% of MenB responsible for IMD cannot be grown in culture, and molecular characterization of these cases is often lacking. The aim of the present study was to describe the distribution of MenB subcapsular antigens, comparing their distribution in culture-positive and culture-negative cases.

METHODS

Molecular data regarding clonal complexes and subcapsular antigen variants of the 55 MenB-IMD occurring in Tuscany from 2007 to 2019 were made available, and their distribution between culture-positive and culture-negative cases was compared. Genetic-MATS and MenDeVAR prediction systems were used to assess multicomponent vaccine coverage predictions.

RESULTS

Culture-positive and culture-negative cases presented a similar percentage representation of fHbp subfamilies. Clonal complex 162 was almost constantly associated with fHbp B231/v1.390, Neisserial-heparin-binding-antigen (NHBA) peptide 20, and PorinA P1.22,14 (BAST-3033): these were the most represented antigenic variants, both in culture-positive and culture-negative groups. Point-estimate 4CMenB coverage prediction was 88.5% (84.6%-92.3%).

CONCLUSIONS

Our data demonstrate that non-cultivable meningococci, responsible for IMD, possess genetic variants of subcapsular antigens that are representative of what has been observed in culture. The vaccine-related antigenic epidemiology of MenB is thus similar in both groups. One of the first on-field applications of gMATS and MenDeVAR identifies their major advantage in their accessibility and in the possibility of dynamic data implementation that must be pursued continuously in the future.

Effectiveness and Impact of the 4CMenB Vaccine against Group B Meningococcal Disease in Two Italian Regions Using Different Vaccination Schedules: A Five-Year Retrospective Observational Study (2014-2018)

Background: A few years after the introduction in Italy of a four-component anti-meningococcal B vaccine (4CMenB), we evaluated the effectiveness and impact of vaccination in two regions using different schedules (2, 4, 6, 12 months in Tuscany vs. 7, 9, 15 months in Veneto) through an observational retrospective study. Methods: Vaccination started in 2014 in Tuscany and in 2015 in Veneto; the data collected referred to the period 2006–2018 for Tuscany and 2007–2018 for Veneto. Cases of invasive meningococcal disease due to N. Meningitidis B were identified by culture and/or real-time PCR. Results: In Tuscany, pre-vaccine incidence was 1.96 (95% CL 1.52; 2.40) and dropped to 0.62 (95% CL 0.60; 0.64) in the post-4CMenB era. Evaluating only vaccinated children, post-4CMenB incidence was 0.12 (95% CL 0.08; 0.15). In Veneto pre-vaccine incidence was 1.94 (95% CL 1.92; 1.96) and dropped to 1.34 (95% CL 1.31; 1.38) in the post-4CMenB era. In the vaccinated population, MenB incidence was 0.53 (95% CL 0.50; 0.56). Vaccine effectiveness was 93.6% (95% CL 55.4; 99.1) in Tuscany and 91.0% (95% CL 59.9; 97.9) in Veneto, with mean vaccine coverages of 83.9% and 81.7%, respectively. The overall impact (evaluating both vaccinated and unvaccinated children) was 0.68 (95% CL 0.10; 0.89) in Tuscany and 0.31 (95% CL −0.56; 0.69) in Veneto; the total impact (evaluating only vaccinated children) was 0.94 (95% CL 0.56; 0.99) and 0.90 (95% CL 0.57; 0.97), respectively. The relative case reduction (RCR) was 65% in Tuscany and 31% in Veneto. Considering the vaccinated population, the RCR was equal to 91% and 80%, respectively. Conclusion: In conclusion, 4CMenB appears to have a very high effectiveness in Italy; the impact of vaccination appears greater where the immunization program is started early.

Do HCWs adequately know about meningitis and 4CMenB vaccine and recommend its use to parents? A cross sectional analysis in Campania Region, Italy

Invasive meningococcal disease (IMD) is a severe disease caused by various Neisseria meningitidis serogroups that represents a serious public health problem worldwide. In Italy, serogroups B and C are the major causes of IMD. On 14 January 2013, the European Medicines Agency authorized the use of the first vaccine available to protect against meningococcal serogroup B (4CMenB). The aim of this study was to assess the IMD epidemiology knowledge and 4CMenB vaccine attitudes of healthcare workers (HCWs) with regard to recommending this vaccine for use, vaccine practices and infectious disease control in the Campania region in Italy. A cross-sectional study was conducted among 293 HCWs (49.5% physicians and 46.4% nurses)interviewed using a self-administered questionnaire. The majority of the HCWs had sufficient knowledge about the disease incidence and lethality, but they were less informed about the higher risk age categories and the serogroups most frequently involved. Additionally, their knowledge about the vaccine was poor with regard to the targeted categories and side effects. Approximately30.0% of the HCWs reported incidences of fever and pain and swelling at the injection site. Moreover,32.8% of the HCWs knew that the risk of developing adverse reactions increases when the 4CMenB vaccine is co-administered with other vaccines. Overall, all of the HCWs were convinced that vaccinations are an important instrument for preventing infectious diseases, and they were aware of their central role in promoting the 4CmenB vaccination and their need to be better informed.

Culture and Real-time Polymerase Chain reaction sensitivity in the diagnosis of invasive meningococcal disease: Does culture miss less severe cases?

BACKGROUND

Invasive meningococcal disease (IMD) is a highly lethal disease. Diagnosis is commonly performed by culture or Realtime-PCR (qPCR).

AIMS

Our aim was to evaluate, retrospectively, whether culture positivity correlates with higher bacterial load and fatal outcome. Our secondary aim was to compare culture and qPCR sensitivity.

METHODS

The National Register for Molecular Surveillance was used as data source. Cycle threshold (CT), known to be inversely correlated with bacterial load, was used to compare bacterial load in different samples.

RESULTS

Three-hundred-thirteen patients were found positive for Neisseria meningitidis by qPCR, or culture, or both; 41 died (case fatality rate 13.1%); 128/143 (89.5%) blood samples and 138/144 (95.8%) CSF were positive by qPCR, 37/143 (25.9%) blood samples and 45/144 (31.2%) CSF were also positive in culture. qPCR was 3.5 times (blood) or 3.1 times (CSF) more sensitive than culture in achieving a laboratory diagnosis of IMD (OR 24.4; 95% CI 12.2-49.8; p < .10-4; Cohen's κ 0.08 for blood and OR 49.0; 95% CI 19.1-133.4; p<10-4; Cohen's κ 0.02; for CSF). Positivity of culture did not correlate with higher bacterial loads in blood (mean CT 27.7±5.71, and CT 28.1±6.03, p = 0.739 respectively in culture positive or negative samples) or in CSF (mean CT 23.1±4.9 and 24.7±5.4 respectively in positive or negative CSF samples, p = 0.11).CT values in blood from patients who died were significantly lower than in patients who survived (respectively mean 18.0, range 14-23 and mean 29.6, range 16-39; p<10-17). No deaths occurred in patients with CT in blood over 23. Positive blood cultures were found in 10/25 (40%) patients who died and in 32/163 (19.6%) patients who survived, p = 0.036, OR 2.73; 95% CL 1.025-7.215), however 60% of deaths would have remained undiagnosed with the use of culture only.

CONCLUSIONS

In conclusion our study demonstrated that qPCR is significantly (at least 3 times) more sensitive than culture in the laboratory confirmation of IMD. The study also demonstrated that culture negativity is not associated with lower bacterial loads and with less severe cases. On the other side, in patients with sepsis, qPCR can predict fatal outcome since higher bacterial load, evaluated by qPCR, appears strictly associated with most severe cases and fatal outcome. The study also showed that molecular techniques such as qPCR can provide a valuable addition to the proportion of diagnosed and serotyped cases of IMD.

Carriage rates and risk factors during an outbreak of invasive meningococcal disease due to Neisseria meningitidis serogroup C ST-11 (cc11) in Tuscany, Italy: a cross-sectional study

Background

During 2015–2016 an outbreak of invasive meningococcal disease due to N. meningitidis serogroup C ST-11 (cc11) occurred in Tuscany, Italy. The outbreak affected mainly the age group 20–30 years, men who have sex with men, and the area located between the cities of Firenze, Prato and Empoli, with discos and gay-venues associated-clusters. A cross-sectional-survey was conducted to assess the prevalence and risk factors for meningococcal-carriage, in order to address public health interventions.

Methods

A convenience sample of people aged 11–45 years provided oropharyngeal swab specimens and completed questionnaires on risk factors for meningococcal carriage during a 3 months study-period, conducted either in the outbreak-area and in a control-area not affected by the outbreak (cities of Grosseto and Siena). Isolates were tested by culture plus polymerase chain reaction. Serogroup C meningococcal isolates were further characterized using multilocus sequence typing. Univariate and multivariate analyses were performed to estimate adjusted odds ratios (AORs) for meningococcal carriage.

Results

A total of 2285 oropharyngeal samples were collected. Overall, meningococcal carriage prevalence was 4.8% (n = 110), with nonencapsulated meningococci most prevalent (2.3%; n = 52). Among encapsulated meningococci, serogroup B was the most prevalent (1.8%; n = 41), followed by serogroup Y (0.5%; n = 11) and serogroup C (0.2%; n = 4); one carrier of serogroup E and one of serogroup Z, were also found (0.04%). Three individuals from the city of Empoli were found to carry the outbreak strain, C:ST-11 (cc11); this city also had the highest serogroup C carriage prevalence (0.5%). At the multivariate analyses, risk factors for meningococcal carriage were: illicit-drugs consumption (AOR 6.30; p < 0.01), active smoking (AOR 2.78; p = 0.01), disco/clubs/parties attendance (AOR 2.06; p = 0.04), being aged 20–30 years (AOR 3.08; p < 0.01), and have had same-sex intercourses (AOR 6.69; p < 0.01).

Conclusions

A low prevalence of meningococcal serogroup C carriage in an area affected by an outbreak due to the hypervirulent N. meningitidis serogroup C ST-11 (cc11) strain was found. The city of Empoli had the highest attack-rate during the outbreak and also the highest meningococcal serogroup C carriage-prevalence due to the outbreak-strain. Multivariate analyses underlined a convergence of risk factors, which partially confirmed those observed among meningococcal outbreak-cases, and that should be considered in targeted immunization campaigns.

Electronic supplementary material

The online version of this article (10.1186/s12879-018-3598-3) contains supplementary material, which is available to authorized users.

Awareness, Attitudes, and Practices Toward Meningococcal B Vaccine among Pediatricians in Italy

Background and objectives: Vaccination against bacterial pathogens is decisive for preventing invasive meningococcal disease and pediatricians play a pivotal role in vaccination compliance and coverage. The aim of this study was to investigate awareness, attitude, and practices toward the vaccine against Meningococcal B serogroup (4CMenB) among a sample of Italian pediatricians. Materials and Methods: A cross-sectional study was carried out using an online questionnaire from March to May 2015. Three multivariate logistic regression models were built to identify factors associated with the outcomes of interest. Results: The data showed that 95.5% of the interviewees correctly responded about the availability of 4CMenB vaccine in Italy, while only 28.0% knew the vaccination schedule for children aged two years or under. This knowledge was significantly higher in younger pediatricians and in those who worked a higher number of hours per week. Pediatricians self-reported a positive attitude toward the utility and safety of 4CMenB vaccine. Those pediatricians with a strong positive attitude toward the utility of the vaccine, who knew the vaccination schedules for children of two years or under, and who declared a satisfactory or good knowledge about the vaccine were more likely to inform parents about its availability in Italy, recommend the vaccination, and verify patients’ vaccination status, in their daily practice. Conclusions: The study highlights factors that currently influence pediatricians’ practices regarding the 4CMenB vaccine. The results showed the possible actions recommended to improve physicians’ awareness and behaviors in order to improve the vaccination compliance and invasive meningococcal diseases prevention.

Invasive Meningococcal Disease due to group C N. meningitidis ST11 (cc11): The Tuscany cluster 2015-2016

OBJECTIVES

To describe the cluster of MenC ST11 Invasive Meningococcal Disease (IMD) occurred in Tuscany in the years 2015-2016.

METHODS

A retrospective charts analysis of clinical, epidemiological and microbiological aspects of documented IMD was performed. Prognostic factors for death were evaluated.

RESULTS

Sixty-one patients with IMD in the 2015-2016 period were documented: 28 had meningococcemia, 24 meningitis plus meningococcemia and 9 meningitis. MenC ST11 (cc11) was identified in 48/54 (89%) of the tested strains. All patients, with the exception of three very early death, received timely and appropriate antibiotic therapy and, in selected case, adjunctive therapy with steroids and Pentaglobin®. Forty-one patients recovered (67.3%, mean age: 26 years), 7 had permanent sequelae (11.3%, mean age 31 years) and 13 died (21.3%; mean age: 46 years). In a multivariate analysis, septic shock, purpura fulminans and advanced age were negative prognostic factors, while emergency admittance to a tertiary-care, university hospital, positively influenced the survival rate. The epidemiological analysis of the cluster identified close contacts and recreational environments such as discos as hotspot for MenC transmission. After a massive vaccination campaign, the number of MenC cases reported in Tuscany in 2017 decreased to 10, with no death.

CONCLUSIONS

Vaccination campaign of key populations together with the need for rapid and qualified emergency care of the affected patients seems to be the main lesson learned by the MenC ST11 Tuscany epidemic.

In the Digital Era, Is Community Outrage a Feasible Proxy Indicator of Emotional Epidemiology? The Case of Meningococcal Disease in Sardinia, Italy

The aims of this study were (i) to evaluate the relationship between official data on invasive meningococcal disease cases in Sardinia and the reporting of the cases by a regional online newspaper and (ii) to identify indicators useful for understanding the community outrage related to health events. Cases of meningococcal disease, selected from articles published between 1999 and 2016 on a regional newspaper database, were compared to those reported to the Infectious Disease Information Service. In order to evaluate the equality of the two distribution records, the Kolgomorov Smirnov test for two samples was applied. A community outrage indicator was obtained by calculating the number of published articles for each case of meningococcal disease identified. The outrage indicator was evaluated in comparison with other phenomena: drinking water supply limitation and domestic accidents. Overall, 2724 articles on meningitis/sepsis referring to 89 cases related to meningococcal disease were considered. Significant differences between the distribution of cases officially reported and those found in the newspaper (combined K-S = 0.39; p = 0.08) were not observed. The meningococcal disease outrage indicator showed an average of seven items per case. Comparing the meningococcal disease outrage indicator with those regarding the limitation of drinking water supplies and domestic accidents, a different risk perception by the reference media was found, with the highest outrage for meningococcal disease. The present study supports the role played by emotional factors as behavioral determinants in emerging threats to public health. The analysis of the data allowed us to highlight that the proposed outrage indicator could be a feasible proxy of emotional epidemiology. Finally, data confirm that meningitis is perceived as a highly outrageous health threat.

Spontanuous Demand For Meningococcal B Vaccination: Effects On Appropriateness And Timing

When the meningococcus B vaccine was introduced into Italy in 2017, it was recommended for newborns based on national epidemiological data indicating that they were at greater risk. However, the vaccination service of the local health authority of L'Aquila had already been receiving spontaneous parental requests to provide vaccination for children in lower-risk age groups from the beginning of 2016. We therefore decided to use a self-administered questionnaire in order to investigate the parents’ socio-demographic data; their children's history of other recommended vaccinations (against measles, mumps and rubella, varicella, meningococcus C and, for females, human papilloma virus); the information sources concerning meningococcal vaccination; and the timing of its administration.

The questionnaire was completed by 565 parents, and the results showed that the requests mainly came from the parents of children aged 5–11 years. The children whose mothers had received a high school education and were >35 years old were more likely to have received the first dose after the age of one year and to have perceived pain at the inoculation site, and less likely to have experienced mild general reactions. The requests were mainly trigged by the recommendations of healthcare professionals, and the overloading of the vaccination service led to delays in the administration of the doses after the first. The delays (reported by 74.07% of the parents) were mainly due to organisational problems in the service itself, which led 61.52% of the doses being more appropriately administered by staff working as private physicians inside public health facilities, albeit at extra cost.

These findings indicate that organisational factors and excessive demand had a considerable impact on both the efficacy of the immunisation and its appropriateness.

Meningococcal vaccination in pregnancy

Invasive meningococcal disease causes meningitis and septicemia worldwide with highest rates of disease occurring in children <2 years of age, and in particular young infants. Vaccination during pregnancy has been a successful strategy for prevention of other infections in young infants, most notably tetanus, pertussis and influenza. However, few studies of meningococcal vaccines in pregnancy have been undertaken, and none include the most commonly used current vaccines to prevent disease by capsular groups A, B, C, W and Y. The limited data suggest that the older polysaccharide vaccines are immunogenic, but the impact on prevention of infant disease has not been measured. Further studies of MenB protein vaccines and MenA protein-polysaccharide conjugate vaccines in particular are needed if vaccination in pregnancy is to be utilized as an approach to prevention of meningococcal disease in young infants.

Invasive meningococcal disease in the Veneto region of Italy: a capture-recapture analysis for assessing the effectiveness of an integrated surveillance system

BACKGROUND

Epidemiology of Neisseria meningitidis has been changing since the introduction of universal vaccination programmes against meningococcal serogroup C (MenC) and meningococcal serogroup B (MenB) has now become dominant. This study aimed to analyse the cases reported in institutional data recording systems to estimate the burden of invasive meningococcal diseases (IMDs) and assess the effectiveness of surveillance in Veneto region (Italy).

METHODS

Analysis was performed from 2007 to 2014 on data recorded in different systems: Mandatory Notification System, National Surveillance of Invasive Bacterial Diseases System and Laboratories Surveillance System (LSS), which were pooled into a combined surveillance system (CSS) and hospital discharge records (HDRs). A capture-recapture method was used and completeness of each source estimated. Number of cases with IMD by source of information and year, incidence of IMD by age group, case fatality rate (CFR) and distribution of meningococcal serogroups by year were also analysed.

RESULTS

Combining the four data systems enabled the identification of 179 confirmed cases with IMD, achieving an overall sensitivity of 94.7% (95% CI: 90.8% to 98.8%), while it was 76.7% (95% CI: 73.6% to 80.1%) for CSS and 77.2% (95% CI: 74.1% to 80.6%) for HDRs. Typing of isolates was done in 80% of cases, and 95.2% of the typed cases were provided by LSS. Serogroup B was confirmed in 50.3% of cases. The estimated IMD notification rate (cases with IMD diagnosed and reported to the surveillance systems) was 0.48/100 000 population, and incidence peaked at 6.2/100 000 in children aged <1 year old (60.9% due to MenB), and increased slightly in the age group between 15 and 19 years (1.1/100 000). A CFR of 14% was recorded (8.7% in paediatric age).

CONCLUSIONS

Quality of surveillance systems relies on case ascertainment based on serological characterisation of the circulating strains by microbiology laboratories. All available sources should be routinely combined to improve the epidemiology of IMD and the information used by public health departments to conduct timely preventive measures.

Underestimation of Invasive Meningococcal Disease in Italy

Underestimation is attributable to misdiagnosis, especially in fatal cases, and use of insufficiently sensitive laboratory methods.

Knowing the incidence of invasive meningococcal disease (IMD) is essential for planning appropriate vaccination policies. However, IMD may be underestimated because of misdiagnosis or insufficiently sensitive laboratory methods. Using a national molecular surveillance register, we assessed the number of cases misdiagnosed and diagnoses obtained postmortem with real-time PCR (rPCR), and we compared sensitivity of rPCR versus culture-based testing. A total of 222 IMD cases were identified: 11 (42%) of 26 fatal cases had been misdiagnosed or undiagnosed and were reclassified as IMD after rPCR showed meningococcal DNA in all available specimens taken postmortem. Of the samples tested with both rPCR and culture, 58% were diagnosed by using rPCR alone. The underestimation factor associated with the use of culture alone was 3.28. In countries such as Italy, where rPCR is in limited use, IMD incidence may be largely underestimated; thus, assessments of benefits of meningococcal vaccination may be prone to error.

A Phase 2, Randomized, Active-controlled, Observer-blinded Study to Assess the Immunogenicity, Tolerability and Safety of Bivalent rLP2086, a Meningococcal Serogroup B Vaccine, Coadministered With Tetanus, Diphtheria and Acellular Pertussis Vaccine and Serogroup A, C, Y and W-135 Meningococcal Conjugate Vaccine in Healthy US Adolescents

BACKGROUND

Bivalent rLP2086, targeting meningococcal serogroup B, will extend prevention of meningococcal disease beyond that provided by quadrivalent serogroup ACWY vaccines; coadministration with recommended vaccines may improve adherence to vaccine schedules. This phase 2, randomized, active-controlled, observer-blinded study assessed whether immune responses induced by coadministration of Menactra (meningococcal A, C, Y and W-135 polysaccharide conjugate vaccine [MCV4]) and Adacel (tetanus toxoid, reduced diphtheria toxoid, acellular pertussis vaccine [Tdap]) with bivalent rLP2086 (Trumenba [meningococcal serogroup B vaccine], approved in the United States) were noninferior to MCV4 + Tdap or bivalent rLP2086 alone.

METHODS

Healthy adolescents aged 10 to <13 years received MCV4 + Tdap + bivalent rLP2086, MCV4 + Tdap or bivalent rLP2086. Bivalent rLP2086 response was assessed with serum bactericidal assays using human complement with 2 meningococcal serogroup B test strains expressing vaccine-heterologous factor H-binding protein variants; MCV4 with SBAs using rabbit complement; and Tdap with multiplexed Luminex assays. Safety was evaluated.

RESULTS

Two thousand six hundred forty-eight subjects were randomized. Immune responses to MCV4 + Tdap + bivalent rLP2086 were noninferior to MCV4 + Tdap or bivalent rLP2086 alone. Seroprotective serum bactericidal assays using human complement titers were documented for 62.3%-68.0% and 87.5%-90% of MCV4 + Tdap + bivalent rLP2086 recipients after doses 2 and 3, respectively. A ≥4-fold rise in serum bactericidal assays using human complement titers from baseline was achieved by 56.3%-64.3% and 84.0%-85.7% of subjects after doses 2 and 3, respectively. Bivalent rLP2086 alone induced similar responses. Concomitant administration did not substantially increase reactogenicity compared with bivalent rLP2086 alone.

CONCLUSIONS

Bivalent rLP2086 given concomitantly with MCV4 + Tdap met all noninferiority immunogenicity criteria without a clinically meaningful increase in reactogenicity. MCV4 and bivalent rLP2086 coadministration would provide coverage against the 5 major disease-causing serogroups.

Vaccinating Italian infants with a new multicomponent vaccine (Bexsero®) against meningococcal B disease: A cost-effectiveness analysis

The European Medicines Agency has approved a multicomponent serogroup B meningococcal vaccine (Bexsero®) for use in individuals of 2 months of age and older. A cost-effectiveness analysis (CEA) from the societal and Italian National Health Service perspectives was performed in order to evaluate the impact of vaccinating Italian infants less than 1 y of age with Bexsero®, as opposed to non-vaccination. The analysis was carried out by means of Excel Version 2011 and the TreeAge Pro® software Version 2012. Two basal scenarios that differed in terms of disease incidence (official and estimated data to correct for underreporting) were considered. In the basal scenarios, we considered a primary vaccination cycle with 4 doses (at 2, 4, 6 and 12 months of age) and 1 booster dose at the age of 11 y, the societal perspective and no cost for death. Sensitivity analyses were carried out in which crucial variables were changed over probable ranges. In Italy, on the basis of official data on disease incidence, vaccination with Bexsero® could prevent 82.97 cases and 5.61 deaths in each birth cohort, while these figures proved to be three times higher on considering the estimated incidence. The results of the CEA showed that the Incremental Cost Effectiveness Ratio (ICER) per QALY was €109,762 in the basal scenario if official data on disease incidence are considered and €26,599 if estimated data are considered. The tornado diagram indicated that the most influential factor on ICER was the incidence of disease. The probability of sequelae, the cost of the vaccine and vaccine effectiveness also had an impact. Our results suggest that vaccinating infants in Italy with Bexsero® has the ability to significantly reduce meningococcal disease and, if the probable underestimation of disease incidence is considered, routine vaccination is advisable.

Immunogenicity, Tolerability and Safety in Adolescents of Bivalent rLP2086, a Meningococcal Serogroup B Vaccine, Coadministered with Quadrivalent Human Papilloma Virus Vaccine

BACKGROUND

This study in healthy adolescents (11 to <18 years) evaluated coadministration of quadrivalent human papillomavirus vaccine (HPV-4), with bivalent rLP2086, a meningococcal serogroup B (MnB) vaccine.

METHODS

Subjects received bivalent rLP2086 + HPV-4, bivalent rLP2086 + saline or saline + HPV-4 at 0, 2 and 6 months. Immune responses to HPV-4 antigens were assessed 1 month after doses 2 and 3. Serum bactericidal assays using human complement (hSBAs) with 4 MnB test strains expressing vaccine-heterologous human complement factor H binding protein (fHBP) variants determined immune responses to bivalent rLP2086. Coprimary objectives were to demonstrate noninferior immune responses with concomitant administration compared with either vaccine alone. Additional endpoints included the proportions of subjects achieving prespecified protective hSBA titers to all 4 MnB test strains (composite response) and ≥4-fold increases in hSBA titer from baseline for each test strain after dose 3; these endpoints served as the basis of licensure of bivalent rLP2086 in the US.

RESULTS

The noninferiority criteria were met for all MnB test strains and HPV antigens except HPV-18; ≥99% of subjects seroconverted for all 4 HPV antigens. Bivalent rLP2086 elicited a composite response in >80% of subjects and increased hSBA titers ≥4-fold in ≥77% of subjects for each test strain after dose 3. A substantial bactericidal response was also observed in a large proportion of subjects after dose 2. Local reactions and systemic events did not increase with concomitant administration.

CONCLUSIONS

Concomitant administration of bivalent rLP2086 and HPV-4 elicits robust immune responses to both vaccines without increasing reactogenicity compared with bivalent rLP2086 alone. Concurrent administration may increase compliance with both vaccine schedules.

A phase 3, randomized, active-controlled study to assess the safety and tolerability of meningococcal serogroup B vaccine bivalent rLP2086 in healthy adolescents and young adults

BACKGROUND

Neisseria meningitidis serogroup B (MnB) is an important cause of invasive meningococcal disease (IMD). A MnB vaccine (bivalent rLP2086, Trumenba(®)) consisting of 2 factor H binding protein variants received accelerated approval in the United States for the prevention of IMD caused by MnB in individuals 10-25 years of age. This randomized, active-controlled, observer-blind study further assessed the safety and tolerability of bivalent rLP2086.

METHODS

Eligible subjects ≥ 10 to < 26 years were randomized (2:1) to receive bivalent rLP2086 at months 0, 2, and 6, or hepatitis A virus vaccine (HAV, Havrix(®)) at months 0 and 6, and saline at month 2. The primary endpoints were serious adverse events (SAEs) throughout the study and medically-attended adverse events (MAEs) within 30 days after vaccination. Additional safety assessments included SAEs at other study intervals and adverse events (AEs) during the vaccination phase.

RESULTS

Of 5712 subjects randomized, 84.6% (n = 3219) of bivalent rLP2086 recipients and 87.2% (n = 1663) of HAV/saline recipients completed the study. Throughout the study, SAEs were reported for 1.6% and 2.5% of bivalent rLP2086 and HAV/saline recipients, respectively. SAEs related to either vaccine were rare. MAEs occurred in 7.0% and 6.1% of subjects after vaccination 1; 5.5% and 6.1% after vaccination 2; and 5.3% and 5.5% after vaccination 3 in the bivalent rLP2086 and HAV/saline groups, respectively. A greater proportion of subjects reported AEs during the vaccination phase after bivalent rLP2086 compared with HAV/saline recipients; however, when reactogenicity events were excluded, the proportion between groups was similar.

CONCLUSION

This safety study, the largest randomized, active-controlled trial evaluating a recombinant MnB vaccine, demonstrated that bivalent rLP2086 is safe and tolerable in healthy individuals ≥ 10 to < 26 years of age.

The burden of bacteremia and invasive diseases in children aged less than five years with fever in Italy

Background

Invasive diseases (ID) caused by Streptococcus pneumoniae (S. pneumoniae), Haemophilus influenzae (H. influenzae), and Neisseria meningitidis are a major public health problem worldwide. Comprehensive data on the burden of bacteremia and ID in Italy, including data based on molecular techniques, are needed.

Methods

We conducted a prospective, multi-centre, hospital-based study (GSK study identifier: 111334) to assess the burden of bacteremia and ID among children less than five years old with a fever of 39 °C or greater. Study participation involved a single medical examination, collection of blood for polymerase chain reaction (PCR) and blood culture, and collection of an oropharyngeal swab for colonization analysis by PCR.

Results

Between May 2008 and June 2009, 4536 patients were screened, 944 were selected and 920 were enrolled in the study. There were 225 clinical diagnoses of ID, 9.8 % (22) of which were bacteremic. A diagnosis of sepsis was made for 38 cases, 5.3 % (2) of which were bacteremic. Among the 629 non-ID diagnoses, 1.6 % (10) were bacteremic. Among the 34 bacteremic cases, the most common diagnoses were community-acquired pneumonia (15/34), pleural effusion (4/34) and meningitis (4/34). S. pneumoniae was the most frequently detected bacteria among bacteremic cases (29/34) followed by H. influenzae (3/34). Ninety percent (27/30) of bacteremic patients with oropharyngeal swab results were colonized with the studied bacterial pathogens compared to 46.1 % (402/872) of non-bacteremic cases (p < 0.001). PCV7 (7-valent pneumococcal conjugate vaccine) vaccination was reported for 55.9 % (19/34) of bacteremic cases. S. pneumoniae serotypes were non-vaccine serotypes in children who had been vaccinated. Mean duration of hospitalization was longer for bacteremic cases versus non-bacteremic cases (13.6 versus 5.8 days).

Conclusions

These results confirm that S. pneumoniae is one of the pathogens frequently responsible for invasive disease.

Acceptability of meningococcal serogroup B vaccine among parents and health care workers in Italy: a survey

A new meningococcal serogroup B vaccine (4 CMenB) has recently been licensed. This study assessed the acceptability of 4 CMenB vaccine among parents and healthcare workers (HCWs). From May to July 2013 in Milan, Italy, self-administered questionnaires were distributed to 2050 parents of infants presenting at immunization clinics for the mandatory hexavalent vaccination and submitted to 350 HCWs involved in immunization practices. 1842 parents (89.1%) responded to the survey; 64.4% of parents wanted their child to receive the 4 CMenB vaccine and 5.1% would not vaccinate their children. Multivariate analysis showed that recognition of the severity of meningitis [a life threatening vs a mild or unthreatening disease (Odds ratio (OR): 2.3; confidence interval (CI): 1.4-3.6], awareness of vaccination as a beneficial preventive measure (very beneficial vs not beneficial OR = 6.4; CI 3.0-13.7) and knowledge of the Meningococcal C vaccine (OR = 1.4; CI 1.1-1.8) were strongly associated to willingness to receive 4 CMenB vaccine. On the contrary, level of education was associated with refusal of immunization (university vs education level lower than middle school OR = 0.68; CI 0.47-0.97). Among the parents who were willing to immunize their children, 66.9% would agree with three injections to be administered during the same visit. A total of 291 HCWs (83.1%) agreed to participate in the survey; 73% considered 4 CMenB vaccine a priority in infants' immunization schedule; 26.8% of HCWs suggested the concomitant administration with routine infant immunization. Parental and HCWs acceptability of 4 CMenB vaccine was high. Increasing knowledge about meningitis and vaccine prevention might further increase the acceptability of this vaccine.

Estimation of the Impact of Meningococcal Serogroup C Universal Vaccination in Italy and Suggestions for the Multicomponent Serogroup B Vaccine Introduction

In Italy, the meningococcal C conjugate vaccine (MenC) has been offered in most regions since 2009-2010. The incidence of Invasive Meningococcal Disease (IMD) was 0.25 confirmed cases per 100,000 in 2011, but this may be considerably underestimated due to underdetection and underreporting. This study estimates the impact of the MenC universal vaccination (URV) in the Puglia region by assessing the completeness of three registration sources (notifications, hospitalizations, and laboratory surveillance). Capture-recapture analysis was performed on meningococcal meningitis collected within 2001-2013. The impact of URV among ≤ 18-year-olds was assessed by attributable benefit, preventable fraction, and prevented fraction. Missed opportunities for vaccination were evaluated from surveillance of IMD. The proportion of detected serogroups was applied to the number of IMD in the postvaccination period to compute the cases still preventable. The sensitivity of the three sources was 36.7% (95% CI: 17.5%-57.9%) and registrations lost nearly 28 cases/year in the period. Attributable benefit of URV was -0.5 cases per 100,000, preventable fraction 19.6%, and prevented fraction 31.3%. Three adolescent cases missed the opportunity to be vaccinated. The multicomponent serogroup B meningococcal vaccine has the potential to further prevent at least three other cases/year. Vaccination strategy against serogroup B together with existing programmes makes IMD a 100% vaccine-preventable disease.

Meningococcal B Vaccination (4CMenB) in Infants and Toddlers

Neisseria meningitidis is a Gram-negative pathogen that actively invades its human host and leads to the development of life-threatening pathologies. One of the leading causes of death in the world, N. meningitidis can be responsible for nearly 1,000 new infections per 100,000 subjects during an epidemic period. The bacterial species are classified into 12 serogroups, five of which (A, B, C, W, and Y) cause the majority of meningitides. The three purified protein conjugate vaccines currently available target serogroups A, C, W, and Y. Serogroup B has long been a challenge but the discovery of the complete genome sequence of an MenB strain has allowed the development of a specific four-component vaccine (4CMenB). This review describes the pathogenetic role of N. meningitidis and the recent literature concerning the new meningococcal vaccine.

Changing epidemiology of Infant Meningococcal Disease after the introduction of meningococcal serogroup C vaccine in Italy, 2006-2014

BACKGROUND

In Italy, the incidence of Invasive Meningococcal Disease (IMD) was around 0.28 per 100,000 over the last years. Since the risk IMD is usually high among infants aged less than 1 year, we decided to evaluate the trend of IMD cases reported between 2006 and 2014 in this age group. In particular, the study aim was to describe the main characteristics of IMD cases in infants following the introduction of MCC vaccine (2005) and to estimate the number of cases which are potentially preventable through early vaccination.

METHODS

The National Surveillance System of Bacterial Meningitis was established in 1994 and in 2007 was extended to all invasive bacterial diseases. Clinical data and isolates and/or clinical samples are collected from hospitalized patients throughout the country. IMD cases are reported by clinicians to the local health authorities, and samples are sent to the Reference Laboratory at the Istituto Superiore di Sanità for further characterization and storage at -80°C. In particular, serogroup identification is obtained by agglutination with commercial antisera or by multiplex PCR.

RESULTS

The annual incidence for infants <1 year old remained rather stable of 3.6 per 100,000, with several upward and downward oscillations and a peak in 2010. The incidence of IMD among infants was more than 10 times higher than the overall rate of IMD observed in Italy. Finally, serogroup B was more frequently detected among infants aged <1 year, accounting for 65% of the total (p<0.01).

CONCLUSIONS

During the study period, IMD incidence reported among infants aged less than one year old was 10 times higher than the overall rate, and serogroup B was the most commonly detected over time. The long-term impact of meningococcal C conjugate vaccine and the effect of the introduction of meningococcal B vaccination among infants need to be evaluated.