Incidence Of Meningococcal Disease Research Articles

Estimating the potential number of cases prevented by infant/ toddler immunisation with a MenACWY vaccine

Introduction: Meningococcal disease control in the UK relies on various vaccines, with the discontinuation of the Hib/MenC combination vaccine Menitorix® in 2018 necessitating reassessment of the immunisation strategy. The quadrivalent MenACWY vaccine emerges as a promising long-term solution, already integrated into the teenage immunisation regimen. While indirect control of group W and C cases is anticipated through existing programs, the high incidence of meningococcal disease in infancy underscores the potential benefits of infant/toddler vaccination.Methods: Utilizing data from two UK studies, we recalibrated age-specific carriage prevalence curves and estimated the proportion of meningococcal carriage attributed to ACWY and non-ACWY strains. Employing a dynamic transmission model, we evaluated the combined indirect effects of the teenage MenACWY vaccination initiative and the direct impact of administering MenACWY vaccine at either 3 or 12 months, alongside ongoing 4CMenB vaccination efforts. Given the pandemic-induced decline in cases and alterations in social contact patterns reported in prior research, we also simulated the transmission model to reflect periods of COVID-19 lockdown.Results: Our projections indicate effective control of carriage and disease associated with groups A, C, W, and Y through the teenage vaccination campaign. Assuming sustained high uptake of teenage vaccines amid pandemic scenario, we forecast MenACWY carriage prevalence to be below 1% by 2025. Across all scenarios, the impact of an infant/toddler MenACWY program on case reduction remains modest. Notably, administering the MenACWY dose at 3 months yields a greater number of prevented cases compared to administration at 12 months. With sustained uptake of teenage vaccination, our estimates suggest that between 3 and 22 cases could be averted in a 2025 birth cohort through a 3-month MenACWY dose.Conclusions: Provided teenage uptake remains high and the infant 4CMenB programme is maintained, we suggest that few cases will be prevented from an infant/ toddler MenACWY dose.

Genomic Surveillance of Invasive Meningococcal Disease During a National MenW Outbreak in Australia, 2017-2018.

In Australia, invasive meningococcal disease (IMD) incidence rapidly increased between 2014 and 2017 due to rising serogroup W (MenW) and MenY infections. We aimed to better understand the genetic diversity of IMD during 2017 and 2018 using whole genome sequencing data. Whole genome sequencing data from 440 Australian IMD isolates collected during 2017 and 2018 and 1737 international MenW:CC11 isolates collected in Europe, Africa, Asia, North America, and South America between 1974 and 2020 were used in phylogenetic analyses; genetic relatedness was determined from single-nucleotide polymorphisms. Australian isolates were as follows: 181 MenW (41%), 144 MenB (33%), 88 MenY (20%), 16 MenC (4%), 1 MenW/Y (0.2%), and 10 nongenogroupable (2%). Eighteen clonal complexes (CCs) were identified, and 3 (CC11, CC23, CC41/44) accounted for 78% of isolates (343/440). These CCs were associated with specific serogroups: CC11 (n = 199) predominated among MenW (n = 181) and MenC (n = 15), CC23 (n = 80) among MenY (n = 78), and CC41/44 (n = 64) among MenB (n = 64). MenB isolates were highly diverse, MenY were intermediately diverse, and MenW and MenC isolates demonstrated the least genetic diversity. Thirty serogroup and CC-specific genomic clusters were identified. International CC11 comparison revealed diversification of MenW in Australia. Whole genome sequencing comprehensively characterized Australian IMD isolates, indexed their genetic variability, provided increased within-CC resolution, and elucidated the evolution of CC11 in Australia.

Analyzing the dynamics of meningococcal vaccinations initiatives by local government units in Poland (2017–2021) – Scope, challenges and recommendations

IntroductionMeningococcal vaccinations are recommended by Polish public health authorities but lack coverage under health insurance, prompting Local Government Units (LGUs) to implement local health policy programs. This study examines the effectiveness and impact of LGU-driven meningococcal vaccination initiatives in Poland between 2017 and 2021. Material and MethodsA retrospective analysis utilized data from reports on local public health interventions submitted annually to the Ministry of Health in Poland. The study focused on the number of meningococcal vaccination programs, their scope, the vaccinated population, and associated program costs. Additionally, nationwide data on meningococcal disease incidence and vaccine uptake were analyzed. ResultsWithin LGUs programs, 48,617 individuals received meningococcal vaccinations, constituting approximately 10% of all vaccinations in Poland during the study period. Notably, cities with poviat rights spearheaded programs covering 54% of the total participants. The total cost incurred by these initiatives amounted to EUR 2,553,661. ConclusionsWhile LGUs activities positively contributed to increased meningococcal vaccination rates, the overall engagement of local governments remains limited. The findings underscore the importance of expanding local government involvement in meningococcal vaccination programs to address public health needs effectively. Improved collaboration and increased funding may enhance the reach and impact of these initiatives.

Differences in meningococcal disease incidence by health insurance type and among persons experiencing homelessness-United States, 2016-2019.

Meningococcal disease is a serious but rare disease in the United States. Prior publications suggest incidence differs among privately vs publicly-insured persons, and that incidence is higher among persons experiencing homelessness (PEH) than persons not known to be experiencing homelessness (non-PEH). Using insurance claims data for persons aged <1 to 64 years, we calculated meningococcal disease incidence among a population with employer-sponsored commercial insurance and persons enrolled in state Medicaid programs nationwide. We also examined meningococcal disease incidence by PEH status in Medicaid data. From 2016 through 2019, persons who met our study inclusion criteria contributed a total of 84,460,548 person-years (PYs) to our analysis of commercial insurance data and 253,496,622 PYs to our analysis of Medicaid data. Incidence was higher among persons enrolled in Medicaid (0.12 cases per 100,000 PYs) than persons with commercial insurance (0.06 cases per 100,000 PYs). Incidence was 3.17 cases per 100,000 PYs among PEH in Medicaid, 27 times higher than among non-PEH in Medicaid. Understanding the underlying drivers of the higher meningococcal disease incidence among PEH and persons enrolled in Medicaid may inform prevention strategies for populations experiencing a higher burden of disease.

Antibodies against Neisseria meningitidis serogroups A, C, W and Y in serum and saliva of Norwegian adolescents

IntroductionThe incidence of invasive meningococcal disease (IMD) among Norwegian 16–19-year-olds was 1–7/100,000 in the decade before the COVID-19 pandemic, with serogroup Y (MenY) dominance. In contrast to many other European countries, meningococcal vaccines are not part of the national immunisation program (NIP) in Norway. This cross-sectional study aimed to measure the degree of natural immunity against Neisseria meningitidis among adolescents in Norway to evaluate the need for introducing tetravalent meningococcal conjugate vaccine (MCV4) in the NIP. Materials and methodsSerum and saliva samples were collected from students in upper and lower secondary schools in Norway in 2018. Samples were analysed for meningococcal capsular polysaccharide (PS)-specific antibodies using a bead-based multiplex immunoassay. PS-specific antibody levels were linked to data on meningococcal carriage, vaccination status and risk factors for carriage (assessed with questionnaire) and analysed by linear regression of log transformed concentrations. A subset of samples from unvaccinated individuals was analysed for serum bactericidal antibodies (SBA). ResultsA total of 1344 participants, median age 16 years (range 12–24), were included in the study. Overall, 60.9% of the participants were female and 1137 (84.6%) were not vaccinated with MCV4. PS-specific antibody concentrations in serum and saliva were low among unvaccinated individuals for all serogroups and only 6.7–20.0% of the subpopulation with high PS-specific antibodies assessed with SBA had protective levels. Unvaccinated MenY carriers had higher levels of MenY anti-PS IgG in serum and IgA in saliva than those not carrying MenY. Use of Swedish snus was associated with lower anti-PS IgG levels in serum and waterpipe use with lower anti-PS IgG levels in saliva. ConclusionUnvaccinated adolescents in Norway have a low degree of natural immunity against the serogroups of N. meningitidis predominating among cases of IMD in this age group. Therefore, introduction of MCV4 for adolescents in the NIP is recommended.

Hypervirulent Strains of Neisseria meningitidis and Clinical Manifestations in Children With Invasive Meningococcal Disease.

Hypervirulent clonal complex (cc) have been associated with higher incidence and case fatality rate of invasive meningococcal disease (IMD). The aim of this study was to describe the clinical manifestations of the hypervirulent cc of meningococcus in children. Retrospective study in patients hospitalized by IMD microbiologically confirmed at three children's tertiary health care centers in Santiago, Chile, between 2010 and 2018. Demographic, clinical information and determination of the cc and factor H binding protein (fHbp) alleles were performed. In total 93 cases were evaluated, sequence typing was available for 91 cases, and 87 (95.6%) had a cc assigned; 63.7% were MenW and 31.8% MenB. The median age was 9 months, 67% were male and 18.7% had any comorbidity. A 26.4% presented neurological deficit, 25.3% petechiae and 20% diarrhea. Sixty-seven percent were admitted to the pediatric intensive care unit (PICU) and the case fatality rate was 9.9%. Regarding cc and fHbp alleles, ST11, ST41/44 and allele 22 were the most frequently identified, with 63.7%, 19.8% and 72.5%, respectively. We found statistically significant differences between the cc and presence of petechiae, diagnosis of meningococcemia plus meningitis, admission and days in PICU and advanced support. Allele 22 for fHbp was associated with the absence of petechiae, low suspicion of IMD, less diagnosis of meningitis+meningococcemia, PICU admission, advanced support and adrenal insufficiency. Epidemiological and microbiological surveillance of IMD should integrate clinical and laboratory components, including molecular and genetic characterization, to enrich the dynamic understanding of the clinical evolution of IMD.

Meningococcal Purpura Fulminans After Rectal Sexual Intercourse in Men Having Sex With Men

Abstract Over the past few decades, the incidence of meningococcal disease in the United States has been steadily declining and has reached historic lows. Much of this decrease in numbers of cases is attributed to the effectiveness and acceptance of immunization with conjugate meningococcal vaccines. Although the Advisory Committee on Immunization Practices has expanded its recommendation for vaccination to include all persons older than 2 years with HIV infection, uninfected men who have sex with men (MSM) without other underling conditions have never been singled out for vaccination. However, outbreaks of invasive meningococcal infection in MSM have been reported in recent years, including the largest and most recent one in Florida. The increased rate of urogenital and anorectal colonization with Neisseria meningitidis in MSM and risk of sexual transmission suggests that MSM, regardless of HIV status, should also be vaccinated against meningococcal disease.

Modelling the impact of COVID-19 and routine MenACWY vaccination on meningococcal carriage and disease in the UK.

Country-wide social distancing and suspension of non-emergency medical care due to the COVID-19 pandemic will undoubtedly have affected public health in multiple ways. While non-pharmaceutical interventions are expected to reduce the transmission of several infectious diseases, severe disruptions to healthcare systems have hampered diagnosis, treatment, and routine vaccination. We examined the effect of this disruption on meningococcal disease and vaccination in the UK. By adapting an existing mathematical model for meningococcal carriage, we addressed the following questions: What is the predicted impact of the existing MenACWY adolescent vaccination programme? What effect might social distancing and reduced vaccine uptake both have on future epidemiology? Will catch-up vaccination campaigns be necessary? Our model indicated that the MenACWY vaccine programme was generating substantial indirect protection and suppressing transmission by 2020. COVID-19 social distancing is expected to have accelerated this decline, causing significant long-lasting reductions in both carriage prevalence of meningococcal A/C/W/Y strains and incidence of invasive meningococcal disease. In all scenarios modelled, pandemic social mixing effects outweighed potential reductions in vaccine uptake, causing an overall decline in carriage prevalence from 2020 for at least 5years. Model outputs show strong consistency with recently published case data for England.

Characteristics of Meningococcal Invasive Disease in Neonates and Virulence of the Corresponding Isolates

Background: The highest incidence of invasive meningococcal disease (IMD) is observed in infants. However, its prevalence in neonates (≤28 days of age) and the characteristics of the corresponding isolates are less described. This report aimed to analyze meningococcal isolates from neonates. Methods: We first screened the database of the national reference center for meningococci in France for confirmed neonatal IMD cases between 1999 and 2019. We then performed whole-genome sequencing on all cultured isolates, and we evaluated their virulence in a mouse model. Results: Fifty-three neonatal cases of IMD (mainly bacteremia) were identified (50 culture-confirmed cases and 3 PCR-confirmed cases) of a total of 10,149 cases (0.5%) but represented 11% of cases among infants of under 1 year of age. Nine cases (17%) occurred among neonates of 3 days of age and younger (early onset). The neonate isolates were often of serogroup B (73.6%) and belonged to the clonal complex CC41/44 (29.4%) with at least 68.5% of coverage by vaccines against serogroup B isolates. The neonatal isolates were able to infect mice although to variable levels. Conclusion: IMD in neonates is not rare and can be of early or late onsets suggesting that anti-meningococcal vaccination can target women planning to have a baby.

Whole genome sequence analysis of Neisseria meningitidis strains circulating in Kazakhstan, 2017-2018.

Neisseria meningitidis (meningococcus) is a cosmopolitan bacterium that is often found in the upper respiratory tract of asymptomatic humans. However, N. meningitidis also causes meningeal inflammation and/or sepsis in humans with a periodic resurgence in incidence and high mortality rates. The pathogen is highly diverse genetically and antigenically, so that genotyping is considered important for vaccine matching to circulating strains. Annual incidence of meningococcal disease in Kazakhstan ranges between 0.2 and 2.5 cases per 100 thousand population. In total, 78 strains of N. meningitidis were isolated from clinical patients and contact persons during the years 2017-2018 in Kazakhstan. Of these, 41 strains including four from the patients and 37 from contacts, were sequenced using Illumina MiSeq. In silico typing was completed using the Neisseria pipeline 1.2 on the Galaxy Workflow Management System and PubMLST. Whole genome SNP (single nucleotide polymorphisms) trees were built using BioNumerics 8. Seven-gene multilocus sequence typing (MLST) identified ten sequence types (ST), two of which have not been previously described (ST-16025; ST-16027). ST-16025 was detected in two patients with invasive meningococcal disease in 2017 and 2018 in Akmola region and 16 contacts in 2017 in Turkistan region. This prevalent type ST-16025 demonstrates considerable intertypic diversity as it consists of three subcomplexes with a distance of more than 2000 SNPs. Invasive and carrier strains belong to different serogroups (MenB and MenC), PorA and FetA_VR. Two invasive strains were MenB, one MenC and one MenW (Hajj lineage). The strains from the contact persons were: MenC (n = 18), cnl (n = 9), MenY (n = 7), MenW (n = 1), MenB (n = 1) and one unidentifiable. Different numbers of alleles were present: 12, 11, 7, and 7 alleles for PorA, FetA, fHbp, and NHBA, respectively. This study is the first report of the genetic diversity of N. meningitidis strains in Kazakhstan. Despite limitations with the studied sample size, important conclusions can be drawn based on data produced. This study provides evidence for regulatory authorities with regard to changing routine diagnostic protocols to increase the collecting of samples for WGS.

Purulent Bacterial Meningitis in the Russian Federation: Epidemiology and Immunization

Relevance: Purulent bacterial meningitis and invasive meningococcal disease remain relevant throughout the world and are of particular concern due to high mortality and disability rates, as well as regular outbreaks of meningococcal infections. Objective: To establish epidemiological features of purulent bacterial meningitis and meningococcal disease in the Russian Federation and to highlight the problem of immunization. Materials and methods: Data were collected at the Russian Reference Center for Bacterial Meningitis Monitoring of the Central Research Institute of Epidemiology in the personified system for registering cases of purulent bacterial meningitis, including meningococcal disease, meningitis of non-meningococcal and unknown etiology. We examined 28,440 registered cases. Results: We established that three pathogens, that is, meningococcus, pneumococcus and Haemophilus influenzae, accounted for 84 % of all cases of bacterial meningitis, the most vulnerable age group being children under 5 years of age. Despite a general decrease in the incidence of purulent bacterial meningitis in the Russian Federation in 2010–2019, we noted an increasing incidence of pneumococcal meningitis and invasive meningococcal disease by the end of the study period. In terms of age, the 10-year observation period demonstrated a decrease in the incidence of invasive meningococcal disease in children and its rise among adolescents and young adults; an increase in the incidence of pneumococcal meningitis in adults and a null decrease in children; and the absence of a downward trend in the incidence of Haemophilus meningitis in children. Discussion: Organization of epidemiological monitoring of bacterial meningitis within the system of epidemiological surveillance in the Russian Federation in 2010, its testing and 12-year implementation has enabled us to trace changes in the incidence, mortality, and fatality of the disease and to establish age groups at risk. To reduce the burden of the disease, it is expedient to further improve the existing immunization programs in the Russian Federation.

Impact of COVID-19 Containment Strategies and Meningococcal Conjugate ACWY Vaccination on Meningococcal Carriage in Adolescents.

Objectives:To examine if COVID-19 containment strategies were associated with reduced pharyngeal carriage of meningococci in adolescents. Also, to observe if carriage prevalence of meningococcal A, C, W and Y differed in meningococcal conjugate ACWY vaccinated and unvaccinated adolescents.Design:Repeat cross-sectional study of pharyngeal carriage.Setting:In 2020, recruitment commenced from February to March (pre-COVID-19) and recommenced from August to September (during COVID-19 measures) in South Australia.Participants:Eligible participants were between 17 and 25 years of age and completed secondary school in South Australia in 2019.Results:A total of 1338 school leavers were enrolled in 2020, with a mean age of 18.6 years (standard deviation 0.6). Pharyngeal carriage of disease-associated meningococci was higher during the COVID-19 period compared with the pre-COVID-19 period (41/600 [6.83%] vs. 27/738 [3.66%]; adjusted odds ratio [aOR], 2.03; 95% CI: 1.22–3.39; P = 0.01). Nongroupable carriage decreased during COVID period (1.67% vs. 3.79%; aOR, 0.45; 95% CI: 0.22–0.95). Pharyngeal carriage of groups A, C, W and Y was similar among school leavers vaccinated with meningococcal conjugate ACWY (7/257 [2.72%]) compared with those unvaccinated (29/1081 [2.68%]; aOR, 0.86; 95% CI: 0.37–2.02; P = 0.73). Clonal complex 41/44 predominated in both periods.Conclusions:Meningococcal carriage prevalence was not impacted by public health strategies to reduce severe acute respiratory syndrome coronavirus 2 transmission and is unlikely to be the mechanism for lower meningococcal disease incidence. As international travel resumes and influenza recirculates, clinicians must remain vigilant for signs and symptoms of meningococcal disease. Vaccinating people at the highest risk of invasive meningococcal disease remains crucial despite containment strategies.

Estimation of the incidence of invasive meningococcal disease using a capture–recapture model based on two independent surveillance systems in Catalonia, Spain

ObjectivesInvasive meningococcal disease (IMD) is an urgent notifiable disease and its early notification is essential to prevent cases. The objective of the study was to assess the sensitivity of two...

Epidemiology of invasive meningococcal disease in Canada, 2012-2019.

A variety of routine childhood and adolescent meningococcal vaccination programs using monovalent (serogroup C) and quadrivalent (A, C, Y, W) conjugate vaccines have been implemented in Canada since 2002, resulting in a decrease in invasive meningococcal disease (IMD) incidence, particularly in serogroup C. Meningococcal vaccines have also been used for outbreak response, including the multicomponent vaccine serogroup B vaccine. This report describes the epidemiology of IMD in Canada from 2012 to 2019. Case data were obtained from the National Enhanced IMD Surveillance System between January 1, 2012 and December 31, 2019. Isolates were sent to the National Microbiology Laboratory for confirmation of serogroup and further studies including phenotype and clonal complex identification. A total of 983 cases of IMD were reported between 2012 and 2019. Overall, the age-adjusted incidence of IMD from 2012 to 2019 was 0.34 cases per 100,000 population per year when standardized to the Canadian 2011 population age distribution (95% CI: 0.32-0.36). Infants younger than one year of age had the highest average age-specific incidence rate (3.6 cases per 100,000 population per year, 95% CI: 2.8-4.3). The highest age-adjusted incidence rate was associated with serogroup B (0.17 cases per 100, 000 population per year, 95% CI: 0.16-0.19). Prior to 2015, most invasive serogroup W isolates were identified as clonal complex 22 (ST-22 CC) and the increase in serogroup W in Canada in recent years has been associated with the replacement of the endemic ST-22 CC with the hyper-virulent ST-11 CC. Invasive meningococcal disease is a rare but severe infection in Canada that mostly affects the very young. Serogroup B continues to account for the greatest proportion of disease. Serogroup W associated with ST-11 CC is becoming a growing contributor of disease in all age groups not protected by serogroup W-containing vaccines.

Population-based study of influenza and invasive meningococcal disease among Greek children during the COVID-19 pandemic

BackgroundAiming to the containment of the coronavirus disease 2019 (COVID-19) pandemic, governments worldwide have implemented a series of non-pharmaceutical interventions. Many of them and especially school closures have impacted the...

Impact of meningococcal C conjugate vaccine on incidence of invasive meningococcal disease in an 18-year time series in Brazil and in distinct Brazilian regions.

To evaluate the impact of meningococcal C conjugate (MCC) vaccine in Brazil. Ecological study assessing all invasive meningococcal disease (IMD) and meningococcal C disease (MenC) cases reported in all age groups, from 2001 to 2019. MCC was implemented in 2010. Data were collected on the DATASUS platform. Joinpoint regression was performed to assess the annual percent change (APC) of the incidence rate. Invasive meningococcal disease incidence decreased in all Brazilian regions from 2001 onwards, without apparent additional reduction attributable to MCC vaccine in the North, Northeast and South. The higher and statistically significant APC reduction in all age groups, in the North and South, and in children <5years, in the Northeast, occurred between 2001 and 2011 (-15.4%), 2004 and 2012 (-14.4%), and 2001 and 2013 (-10.3%), respectively, before MCC vaccine implementation. Annual incidence of MenC in children under 5years significantly fell in the North (-6.8%; 2011-2018), Southeast (-40.6%; 2010-2015) and Midwest (-48.6%; 2010-2014), which may be attributable to MCC implementation. Invasive meningococcal disease and MenC behaved differently after MCC vaccine implementation in Brazil during this 18-year time-series analysis. This suggests that the control of IMD should be based on multiple public health care measures and considered on a regional basis.

Invasive Meningococcal Disease, 2011-2020, and Impact of the COVID-19 Pandemic, England.

Invasive meningococcal disease incidence in England declined from 1.93/100,000 persons (1,016 cases) in 2010–11 to 0.95/100,000 (530 cases) in 2018–19 and 0.74/100,000 in 2019–20 (419 cases). During national lockdown for the coronavirus disease pandemic (April–August 2020), incidence was 75% lower than during April–August 2019.

MenQuadfi (MenACWY-TT): A New Vaccine for Meningococcal Serogroups ACWY.

This article reviews data encompassing the pharmacology, efficacy, and safety of MenACWY-TT (MenQuadfi), a conjugate vaccine to prevent meningococcal disease from serogroups A, C, W, Y. A literature review was conducted in PubMed, MEDLINE, and ClinicalTrials.gov from inception up to July 2021, using the search terms MenQuadfi, meningococcal ACWY vaccine, MCV4, and menacwy. Articles from reference lists were included to identify potential relevant literature. Data were limited to randomized phase II and III clinical studies published in the English language, evaluating the efficacy and safety of MenACWY-TT. Animal studies and studies not utilizing MenACWY-TT were excluded. One phase II and 4 phase III randomized clinical studies, enrolling approximately 7700 participants, aged 2 years to 97 years old found that MenACWY-TT was noninferior when compared to established MenACWY vaccines, as measured by surrogate immunogenicity end points. In studies evaluating primary dose vaccination, conducted in those aged 2 to 97 years of age, the difference in seroresponse rates, reported by the lower bound of the 95% CI, was (A) 1.1% to 14.8%, (C) 21% to 42.2%, (Y) 7.7% to 24.6%, and (W) 8.9% to 22.5%. Despite the low incidence of meningococcal disease in the United States, meningococcal disease causes significant morbidity and mortality if not prevented. MenACWY-TT is noninferior to currently approved quadrivalent meningococcal vaccines and shows similar immunogenicity and safety as both an initial vaccine for prevention as well as a booster dose.

Antimeningococcal Vaccination Coverage Among Healthcare Workers in an Italian University Hospital.

Introduction: Following an outbreak of meningococcal epidemic in 2015 and 2016 in Tuscany, we registered a higher demand for antimeningococcal vaccination (anti-Men ACWY) by Healthcare Workers of the University Hospital of Pisa [Azienda Ospedaliero Universitaria Pisana (AOUP)]. The purpose of this work is to analyze and discuss data on vaccination coverage resulting from this vaccination campaign.Materials and Methods: We conducted a monocentric study about anti-Men vaccination in the healthcare workers of the AOUP following the outbreak of meningococcal meningitis that occurred mainly in the population of the Tuscan provinces of Pisa, Pistoia, Prato, and Florence. The variables under examination were age, sex, educational qualification, and job profile. Department healthcare workers were vaccinated with two types of conjugated tetravalent vaccines for the A, C, Y, and W135 strains. Data were analyzed using the SPSS software.Results: The total population of the workers in AOUP was 7,188 subjects; the population considered in the study was 5,889. Between 2015 and 2017, a total of 2,423 subjects (41.1%) underwent anti-Men vaccination. Women, older HCWs, those with a lower educational qualification, doctors, and the HCWs of the maternal and child department, and imaging department recorded a statistically significant better vaccine compliance.Discussion: The AOUP, implementing the program of the Tuscany Region of vaccination against Neisseria meningitidis, has contributed to reduce the incidence of invasive meningococcal disease. Some critical issues remain in the compliance of some sections of the population, despite the high level of adherence recorded in this case, probably also due to the great media coverage of the event.

Seroprevalence of meningococcal serogroup C bactericidal antibodies in the Portuguese population, a decade after vaccine introduction in the National Immunisation Programme.

BackgroundThe incidence of invasive meningococcal disease due to serogroup C (MenC) decreased in Portugal since the introduction of the conjugate vaccine (MCC) in the free market in 2001 and in the National Immunisation Plan in 2006. Considering the potential waning of the antibody response reported in the literature, the different vaccination schemes that were used in our country over the past decade, and that Neisseria meningitidis serogroup C continues to circulate, the Portuguese population may currently be at increased risk of infection. In the absence of national data, we evaluated the seroprotection level of the Portuguese population against MenC, in order to identify the protected fraction of the population and ponder on the necessity of a booster dose of the MCC vaccine.MethodsWe measured serum bactericidal antibody levels against MenC in a representative sample of the population (n = 1500) aged 2–64 years who participated in the 2015/2016 National Serological Survey.ResultsA total of 31.1% (466/1500, 95%CI: 29–33%) of the individuals studied were protected against MenC. The geometric mean titre was 6.5. The proportion of seroprotected was particularly low in children aged 2–4 years (<16%) who received a single dose of the vaccine at 12 months of age (vaccination strategy since 2012). The proportion of seroprotected was higher (44.7% to 53.5%) in adolescent and young adults (15–24 years of age), resulting from vaccination during the catch-up campaign at 5–15 years of age. The highest protection rates were observed when the vaccine was administered during adolescence.ConclusionThe small fraction of population seroprotected, combined with the already known waning effect of the antibody response over time, may indicate that the Portuguese population will become progressively more exposed to the risk of infection. Taking in consideration our results, we recommend to change the current vaccination strategy and introduce a booster dose of the MCC vaccine during adolescence.