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BACKGROUND: Invasive meningococcal disease is a serious global health threat in the world; in 2016, the European Centre for Disease Control and Prevention reported 3280 confirmed cases (including 304 deaths) of Invasive Meningococcal Diseases in Europe. In Italy, in 2017 were reported 200 cases 41% of which due to menB serogroup. From January 2013 the European Medicines Agency (EMA) has authorized the marketing of the meningococcal B vaccine 4CMenB. METHODS: The study aimed to evaluate and complement the safety profile of 4CMenB in high risk children accessing the vaccine service of the Bambino Gesù Children's Hospital. All individuals aged six weeks or more receiving the meningococcal 4CMenB (Bexsero®) vaccine that approached the vaccine Centre at the Bambino Gesù Children's Hospital in Rome, were asked to participate. All parents or caregivers of vaccinated individuals in the study period, were recruited and requested to answer to a questionnaire on adverse events following immunization (AEFI) observed after 7 days, starting from the date of vaccination. RESULTS: During the study period (October 2016-October 2017), we collected 157 completed questionnaires (out of 200 distributed). Of those 132 were first doses and 25 were booster administered doses. The median age of the study population was 4.5 years (range 0.29 to 26.8 years), the majority of subjects were high-risk individuals (64%) with chronic health conditions. Overall, 311 adverse events were reported in the 7 days after vaccine administration. In particular 147 events (47%) after administration of first dose and 58 (19%) after the booster doses. A large majority of those events, were of little clinical importance and concentrated in the 24 h after vaccine administration. No hospitalizations or Emergency Department access were reported. CONCLUSIONS: Results of our study demonstrated that the Bexsero® vaccine is almost well tolerated, with a low incidence of severe AEFIs. Our results also shown that the occurrence of AEFIs is similar within healthy and high risk children.

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Gonorrhea is a major global public health problem with emergence of multiple drug-resistant strains with no effective vaccine. This retrospective cohort study aimed to estimate the effectiveness of the New Zealand meningococcal B vaccine against gonorrhea-associated hospitalization. The cohort consisted of individuals born from 1984 to 1999 residing in New Zealand. Therefore, it was eligible for meningococcal B vaccination from 2004 to 2008. Administrative datasets of demographics, customs, hospitalization, education, income tax, and immunization were linked using the national Integrated Data Infrastructure. The primary outcome was hospitalization with a primary diagnosis of gonorrhea. Cox's proportional hazards models were applied with a Firth correction for rare outcomes to generate estimates of hazard ratios. Vaccine effectiveness estimates were calculated as 1-Hazard Ratio expressed as a percentage. There were 1,143,897 eligible cohort members with 135 missing information on gender, 16,245 missing ethnicity, and 197,502 missing deprivation. Therefore, only 935,496 cohort members were included in the analysis. After adjustment for gender, ethnicity, and deprivation, vaccine effectiveness (MeNZB™) against hospitalization caused by gonorrhea was estimated to be 24% (95% CI 1⁻42%). In conclusion, the data suggests vaccination with MeNZB™ significantly reduced the rate of hospitalization from gonorrhea. This supports prior research indicating possible cross protection of this vaccine against gonorrhea acquisition and disease in the outpatient setting.

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INTRODUCTION: Capsular group B meningococcal disease is a leading cause of childhood meningitis and septicaemia. Up to 10% of sufferers die, and sequelae remain in > 30% of survivors. A vaccine, four component meningococcal group B ( 4CMenB ), designed with the aim to induce broad coverage against this highly variable bacterium, has been licensed in countries including in the European Union, Canada and Australia. AREAS COVERED: Immunogenicity and safety data, published in peer-reviewed literature between 2004 and 2014, are presented in the context of the recent recommendation for the use of the vaccine in infants in the UK. EXPERT OPINION: 4CMenB induces significant reactogenicity when administered with routine infant vaccines, in particular with respect to fever rates. Fevers can be somewhat reduced using paracetamol. The efficacy of the vaccine is unknown but has been extrapolated from effectiveness data obtained from use of one of its components in New Zealand, immunogenicity data from clinical trials and estimation of coverage from in vitro studies. These data suggest that the vaccine will prevent a proportion of invasive meningococcal disease cases in infants and young children. Implementation and well-planned post-marketing surveillance will address uncertainties over field effectiveness.

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Objective To investigate the molecular size distribution and the structure of group B me-ningococcal capsular polysaccharides for the development of vaccines .Methods The molecular size distribution of group B meningococcal capsular polysaccharides was analyzed by chromatography on a Sepharose CL -4B col-umn.The molecular weight of repeat units were measured by matrix assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS).The structural characteristics of group B meningococcal capsular polysaccharides were analyzed by nuclear magnetic resonance ( NMR) based on the chemical shift of all charac-teristic protons by using group C meningococcal capsular polysaccharides and sialic acid as the controls .Results The KD value of group B meningococcal capsular polysaccharides extracted from 15 strains were ranged from 0.60 to 0.76.The molecular weight of repeat units was 284, which was identical to the theoretical value .The group B meningococcal capsular polysaccharides were 2→8 linked homopolymers of sialic acid lacking O-acetyl groups.Conclusion The group B meningococcal capsular polysaccharides had lower molecular weights , which might result in their poor immunogenicity .The structure of group B meningococcal capsular polysaccharides could be quickly and accurately analyzed by NMR technology .

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BACKGROUND: 4CMenB (Bexsero), a vaccine developed against invasive meningococcal disease caused by capsular group B strains (MenB), was recently licensed for use by the European Medicines Agency. Assessment of 4CMenB strain coverage in specific epidemiologic settings is of primary importance to predict vaccination impact on the burden of disease. The Meningococcal Antigen Typing System (MATS) was developed to predict 4CMenB strain coverage, using serum bactericidal antibody assay with human complement (hSBA) data from a diverse panel of strains not representative of any specific epidemiology. OBJECTIVE: To experimentally validate the accuracy of MATS-based predictions against strains representative of a specific epidemiologic setting. METHODS AND RESULTS: We used a stratified sampling method to identify a representative sample from all MenB disease isolates collected from England and Wales in 2007-2008, tested the strains in the hSBA assay with pooled sera from infant and adolescent vaccinees, and compared these results with MATS. MATS predictions and hSBA results were significantly associated (P=0.022). MATS predicted coverage of 70% (95% CI, 55-85%) was largely confirmed by 88% killing in the hSBA (95% CI, 72-95%). MATS had 78% accuracy and 96% positive predictive value against hSBA. CONCLUSION: MATS is a conservative predictor of strain coverage by the 4CMenB vaccine in infants and adolescents.

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