The Clinical Picture and Severity of Invasive Meningococcal Disease Serogroup W Compared With Other Serogroups in the Netherlands, 2015-2018

Cost of Illness Analysis of Invasive Meningococcal Disease Caused by Neisseria Meningitidis Serogroup B in the Netherlands-a Holistic Approach

INTRODUCTION

Invasive meningococcal disease (IMD) caused by Neisseria meningitidis is a rapidly progressing, rare disease that often presents as meningitis or sepsis. It mostly affects infants and adolescents, with high fatality rates or long-term sequelae. In the Netherlands, serogroup B (MenB) is most prevalent. We aimed to estimate the economic burden of MenB-related IMD between 2015 and 2019, including direct and indirect medical costs from short- and long-term sequelae, from a societal perspective.

METHODS

IMD incidence was based on laboratory-based case numbers from the Netherlands Reference Laboratory for Bacterial Meningitis (Amsterdam UMC, Amsterdam, the Netherlands); there were 74 MenB cases on average per year in the study period 2015-2019. Case-fatality rate (3.8%) and percentage of patients discharged with sequelae (46%) were derived from literature. Direct costs included treatment costs of the acute phase, long-term sequelae, and public health response. Indirect costs were calculated using the human capital (HCA) and friction costs (FCA) approaches, in which productivity losses were estimated for patients and parents during the acute and sequelae phases. Costs were discounted by 4% yearly.

RESULTS

Estimated costs due to MenB IMD in an annual cohort were €3,094,199 with FCA and €9,480,764 with HCA. Direct costs amounted to €2,974,996, of which 75.2% were related to sequelae. Indirect costs related to sequelae were €52,532 with FCA and €5,220,398 with HCA.

CONCLUSION

Our analysis reflects the high economic burden of MenB-related IMD in the Netherlands. Sequelae costs represent a high proportion of the total costs. Societal costs were dependent on the applied approach (FCA or HCA).

Range of Clinical Manifestations Caused by Invasive Meningococcal Disease Due to Serogroup W: A Systematic Review

INTRODUCTION

Invasive meningococcal disease (IMD) due to serogroup W meningococci (MenW) is consistently reported with atypical clinical manifestations, including gastrointestinal symptoms, bacteremic pneumonia, and septic arthritis. We undertook a systematic review of the literature for a comprehensive assessment of the clinical presentation of IMD caused by MenW.

METHODS

PubMed and Embase databases were searched from inception to June 2022 using a combination of MeSH terms and free text for articles that reported symptoms and signs of MenW IMD, and associated manifestations.

RESULTS

The most commonly reported symptoms identified included: fever (range 36-100% of cases), nausea and/or vomiting (range 38-47%), vomiting (range 14-68%), cough (range 7-57%), sore throat (range 13-34%), headache (range 7-50%), diarrhea (range 8-47%), altered consciousness/mental status (range 7-38%), stiff neck (range 7-54%), and nausea (range 7-20%). Sepsis (range 15-83% of cases) was the most commonly reported manifestation followed by meningitis (range 5-72%), sepsis and meningitis (range 6-74%), bacteremic pneumonia (range 4-24%), arthritis (range 1-15%), and other manifestations (e.g., pharyngitis/epiglottitis/supraglottitis/tonsillitis/conjunctivitis; range 1-24%). The case fatality rates ranged from 8-40%, and among the survivors 4-14% had long-term sequelae.

CONCLUSIONS

Clinicians need to be aware of the nonspecific symptoms and signs of IMD, as well as of the atypical manifestations in regions where MenW is known to circulate to ensure timely diagnoses and treatment.

Epidemiology, clinical features and outcome of adults with meningococcal meningitis: a 15-year prospective nationwide cohort study

Background

We describe the epidemiology, clinical features and outcome of adult meningococcal meningitis in the Netherlands over a 15-year period.

Methods

We studied adults (age ≥ 16 years) who were listed by the Netherlands Reference Laboratory for Bacterial Meningitis and/or included in the prospective nationwide cohort study (MeninGene) between January 2006 and July 2021. Incidences were calculated per epidemiological year (July-June).

Findings

We identified 442 episodes of adult meningococcal meningitis. The median patient age was 32 years (IQR 18-55) and 226 episodes (51%) occurred in female patients. The annual incidence per 100,000 adults fluctuated, from 0.33 in 2006-2007 to 0.05 in 2020-2021, with a temporal increase up to 0.30 from 2016 to 2018, driven by an outbreak of serogroup W (MenW). Of 442 episodes, 274 episodes (62%) in 273 patients were included in the clinical cohort study. The overall case fatality rate was 4% (10 of 274) and 16% (43 of 274) had an unfavourable outcome (Glasgow Outcome Scale score 1-4). Compared to other serogroups, MenW was associated with higher rates of unfavourable outcome (6 of 16 [38%] vs. 37 of 251 [15%], P = 0.03) and death (4 of 16 [25%] vs. 6 of 251 [2%], P = 0.001).

Interpretation

The overall incidence of adult meningococcal meningitis in the Netherlands is low and outcome is generally favourable. An increase of MenW meningitis occurred from 2016 to 2018, which was associated with more unfavourable outcome and death.

Funding

Netherlands Organisation for Health Research and Development, European Research Council, National Institute of Public Health and Environmental protection.

Adolescent and parental decision-making for the MenACWY vaccination: influential predictors and parental-adolescent differences among households in the Netherlands

BACKGROUND

Between 2015 and 2018 The Netherlands experienced increases of invasive meningococcal disease (IMD) serogroup W (MenW). Therefore in 2018 the MenACWY vaccination was introduced in the National Immunisation Programme (NIP) and a catch-up campaign was initiated targeting adolescents. This study aimed to gain insight into what factors played a role in the decision-making process regarding the MenACWY vaccination. The focus was on the differences in the decision-making of parents and adolescents in order to assess what factors influence the decisions made.

METHODS

An online questionnaire was offered to adolescents and one of their parents. We used random forest analyses to determine which factors best predict the outcome of the MenACWY vaccination decision. We carried out ROC (receiver-operator characteristics) analyses to confirm the predictive value of the variables.

RESULTS

Among parents several factors stand out, centring on the process of the decision, their attitude about the MenACWY vaccination, trust in the vaccination, and ideas of important people around them. Among adolescents the three stand-out predictors are the ideas of important people around them, the process of the decision and trust in the vaccination. Parents have prominent influence in the decision-making, while the adolescent's influence in the household decision-making is more limited. Adolescents tend to be less engaged and spend less time thinking about the decision compared to parents. Opinions of parents and adolescents from the same households concerning the factors that are influential do not differ a lot in the final decision-making.

CONCLUSIONS

Information about MenACWY vaccination might be mainly addressed to the parents of the adolescents and whereby the dialogue about MenACWY vaccination between parents and adolescents will be stimulated. With regard to the predictor trust in vaccination, raising the frequency of use of certain sources, especially those deemed very reliable among households such as conversations with a GP or the provider of the vaccination (GGD/JGZ), might prove a useful strategy to solidify vaccination uptake numbers.

The burden of invasive meningococcal disease in the Netherlands, 2011-2020

INTRODUCTION

Representative information on disease course and outcome of invasive meningococcal disease (IMD) is important because of the shift in meningococcal epidemiology that recently occurred in the Netherlands. With this study, we update earlier research on the burden of IMD in the Netherlands.

MATERIAL AND METHODS

We performed a retrospective study using Dutch surveillance data on IMD from July 2011 to May 2020. Clinical information was collected from hospital records. The effect of age, serogroup, and clinical manifestation on disease course and outcome was assessed in multivariable logistic regression analyses. Grouping of infecting isolates was performed by Ouchterlony gel diffusion or by PCR.

RESULTS

Clinical information was collected for 278 IMD cases of which the majority had IMD-B (55%), followed by IMD-W (27%), IMD-Y (13%), and IMD-C (5%). Most patients presented with meningitis (32%) or sepsis (30%). Hospitalisation for ≥ 10 days was most frequent among 24-64 year olds (67%). ICU admission was highest among 24-64 year olds (60%), and in case of sepsis (70%), or sepsis plus meningitis (61%). Sequelae at discharge was lower for patients with mild meningococcaemia compared to patients with sepsis plus meningitis (OR: 0.19, 95% CI: 0.07-0.51). The overall case fatality rate was 7%, and was highest for IMD-Y (14%) and IMD-W (13%) patients.

CONCLUSIONS

IMD remains a disease with high morbidity and mortality. Sepsis (with or without meningitis) is associated with a more severe disease course and outcome compared to other clinical manifestations. The high disease burden can be partly prevented by meningococcal vaccination.

Surveillance of invasive meningococcal disease in southern Brazil: considerations of an immunization programme

Invasive meningococcal disease (IMD) is a major cause of meningitis and septicaemia worldwide. Changes in serogroup predominance contribute to the unpredictable nature of the disease, with significant health impact. This study aimed to determine the epidemiological profile of IMD in Rio Grande do Sul, Santa Catarina and Paraná, three states in southern Brazil. We analysed 1024 IMD cases that had been confirmed by clinical and/or laboratory criteria and reported to the national information system for notifiable diseases between 2015 and 2019. Additionally, we calculated the proportions of serogroup and incidence by age. Of 1024 cases, 562 (55 %) were caused by serogroup C. Furthermore, serogroup W was responsible for almost half of the cases among children younger than 5 years between 2017 and 2018, with an overall incidence of 1.5 cases/100 000 infants. IMD remains a significant healthcare issue in southern Brazil despite reduced serogroup C incidence after the introduction of the meningococcal C conjugate vaccine into the childhood immunization programme. Changes in disease epidemiology were observed, and serogroup W was the most common serogroup among children younger than 5 years in 2017 and 2018. Although future cost-effectiveness studies are necessary, our results could have future implications for meningococcal vaccination programmes.

Immunogenicity and safety of MenACWY-TT, a quadrivalent meningococcal tetanus toxoid conjugate vaccine recently licensed in the United States for individuals ≥2 years of age

Vaccination offers the best way to prevent invasive meningococcal disease (IMD). As demonstrated in countries with national immunization programs (NIPs) against IMD, meningococcal conjugate vaccines have contributed to significant declines in incidence. Since some meningococcal vaccines are associated with modest immunogenicity in infants, possible immunological interference upon concomitant administration with some pediatric vaccines, and administration errors resulting from improper reconstitution, opportunities for improvement exist. A quadrivalent conjugate vaccine, MenQuadfi® (Meningococcal [Serogroups A, C, Y, and W] Conjugate Vaccine; Sanofi, Swiftwater, Pennsylvania), was approved in 2020 for the prevention of IMD caused by meningococcal serogroups A, C, W, and Y in individuals ≥2 years of age in the United States. Five pivotal studies and one ancillary study supported approval in the United States; clinical trials in infants are ongoing. Data on the immunogenicity and safety of this vaccine are presented, and its potential value in clinical practice is discussed.

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

OBJECTIVES

Invasive 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 independent surveillance systems and to estimate the incidence of IMD.

DESIGN

We used capture-recapture model based on two independent surveillance systems, the statutory disease reporting (SDR) system and the microbiological reporting system (MRS) of the Public Health Agency of Catalonia, between 2011 and 2015. The capture-recapture analysis and 95% CIs were calculated using the Chapman formula. Multivariate vector generalised linear model was performed for adjusted estimation.

MEASURES

The variables collected were age, sex, year of report, size of municipality (<10 000 and ≥10 000), clinical form, death, serogroup, country of birth and type of reporting centre (private and public).

RESULTS

The sensitivity of the two combined surveillance systems was 88.5% (85.0-92.0). SDR had greater sensitivity than the MRS (67.9%; 62.7-73.1 vs 64.7%; 59.4-70.0). In 2014-2015, the sensitivity of both systems was higher (80.6%; 73.2-87.9 vs 73.4%; 65.2-81.6) than in 2011-2013 (59.3%; 52.6-66.0 vs 58.3%; 51.6-65.1). In private centres, the sensitivity was higher for SDR than for MRS (100%; 100-100 vs 4.8%; -4.4-13.9). The adjusted estimate of IMD cases was lower than that obtained using the Chapman formula (279; 266-296 vs 313; 295-330). The estimated adjusted incidence of IMD was 0.7/100 000 persons-year.

CONCLUSIONS

The sensitivity of enhanced surveillance through the combination of two complementary sources was higher than for the sources individually. Factors associated with under-reporting in different systems should be analysed to improve IMD surveillance.

One-Year Sequelae and Quality of Life in Adults with Meningococcal Meningitis: Lessons from the COMBAT Multicentre Prospective Study

INTRODUCTION

COMBAT is a prospective, multicentre cohort study that enrolled consecutive adults with community-acquired bacterial meningitis (CABM) in 69 participating centres in France between February 2013 and July 2015 and followed them for 1 year.

METHODS

Patients aged at least 18 years old, hospitalised with CABM were followed during their hospitalisation and then contacted by phone 12 months after enrolment. Here we present the prevalence of sequelae at 12 months in a subgroup of patients with meningococcal meningitis.

RESULTS

Five of the 111 patients with meningococcal meningitis died during initial hospitalisation and two died between discharge and 12 months, leaving 104 patients alive 1 year after enrolment, 71 of whom provided 12-month follow-up data. The median age was 30.0 years and 54.1% of the patients had no identified risk factor for meningitis. More than 30% reported persistent headache, more than 40% were not satisfied with their sleep and 10% had concentration difficulties. Hearing loss was present in about 15% of the patients and more than 30% had depressive symptoms. About 13% of the patients with a previous professional activity had not resumed work. On the SF-12 Health Survey, almost 50% and 30% had physical component or mental component scores lower than the 25th percentile of the score distribution in the French general population. There was a non-significant improvement in the patients' disability scores from hospital discharge to 12 months (p = 0.16), but about 10% of the patients had residual disability.

CONCLUSIONS

Although most patients in our cohort survive meningococcal meningitis, the long-term burden is substantial and therefore it is important to ensure a prolonged follow-up of survivors and to promote preventive strategies, including vaccination.

TRIAL REGISTRATION

ClinicalTrial.Gov identification number NCT01730690.

Sex-Related Differences in the Immune Response to Meningococcal Vaccinations During Adolescence

Background

Immune responses to pediatric vaccinations have been reported to differ according to sex. Such sex-differential responses may become more pronounced during adolescence due to hormonal differences. We investigated whether the vaccine response following primary vaccination against meningococcal serogroup A (MenA), MenW and MenY and booster vaccination against MenC differed between girls and boys using data from two clinical studies.

Methods

Children aged 10, 12, and 15 years, who had been primed with MenC vaccination between 14 months and 6 years of age, received a booster MenC vaccination or MenACWY vaccination. Polysaccharide-specific IgG concentrations and functional antibody titers [determined with the serum bactericidal antibody (SBA) assay] were measured at baseline, 1 month, 1 year, and 3 years (only MenC group) after vaccination. We calculated geometric mean concentrations and titers (GMC and GMT) ratios for girls vs. boys adjusted for age group. Additionally, we compared the proportion protected individuals between girls and boys at all timepoints.

Results

This study included 342 girls and 327 boys from two clinical trials. While MenAWY antibody levels did not differ consistently 1 month after vaccination, all GMC- and GMT-ratios were in favor of girls 1 year after vaccination [range: 1.31 (1.02–1.70) for MenA IgG to 1.54 (1.10–2.16) for MenW IgG]. Overall, MenC antibody levels were slightly higher in girls at all postvaccination timepoints (GMC- and GMT-ratios: 1.16/1.17 at 1 month, 1.16/1.22 at 1 year and 1.12/1.15 3 years postvaccination). Higher MenC antibody levels were observed in 12- and 15-year-old girls compared to boys of the same age, whereas 10-year-old boys and girls had similar antibody levels. The percentage of participants protected (SBA titer ≥ 8) was very high (95–100%) at all timepoints, and did not differ significantly between boys and girls.

Conclusion

Antibody responses were higher in girls than in boys for all serogroups at most timepoints after primary MenAWY vaccination and booster MenC vaccination. The differences in average titers were however small and the percentage participants with protective titers was very high for both sexes.

Risk Factors for Contracting Invasive Meningococcal Disease and Related Mortality: A Systematic Literature Review and Meta-analysis

OBJECTIVES

To describe risk factors (RFs) and quantify their effects in invasive meningococcal disease (IMD) and associated mortality across all age groups based on the available published literature.

METHODS

A systematic literature review (SLR) was conducted via MEDLINE® and Embase. Study selection, data extraction, and quality assessment were performed by two independent reviewers. Associations between RFs and outcomes were quantified via a meta-analysis (MA).

RESULTS

Seventy-four studies (date range 1950 - 2018) were included in the SLR. Statistically significant RFs for contracting IMD identified from the SLR (within-study) included previous IMD infection and young age (0 - 4 years). MA indicated that significant RFs for contracting IMD (11 studies) were: HIV-positive status, passive smoke exposure, and crowded living space. In the MA for IMD-related mortality risk (11 studies), age 25 - 45 years (vs. 0 - 5 years) and serogroup C (vs. serogroup B) were significantly associated with increased risk.

CONCLUSIONS

Previous findings of higher risk for IMD contraction with smoke exposure and crowded living conditions in children/adolescents have been extended by this SLR/MA to all age groups. We provide strong evidence for higher risk of IMD in HIV-positive individuals, and confirm previous findings of higher IMD-related mortality risk in adults aged 25 - 45.

Invasive meningococcal disease in older adults in North America and Europe: is this the time for action? A review of the literature

BACKGROUND

Neisseria meningitidis is an encapsulated Gram-negative diplococcus that asymptomatically colonises the upper respiratory tract in up to 25% of the population (mainly adolescents and young adults). Invasive meningococcal disease (IMD) caused by Neisseria meningitidis imposes a substantial public health burden,. The case fatality rate (CFR) of IMD remains high. IMD epidemiology varies markedly by region and over time, and there appears to be a shift in the epidemiology towards older adults. The objective of our review was to assess the published data on the epidemiology of IMD in older adults (those aged ≥ 55 years)in North America and Europe. Such information would assist decision-makers at national and international levels in developing future public health programmes for managing IMD.

METHODS

A comprehensive literature review was undertaken on 11 August 2020 across three databases: EMBASE, Medline and BIOSIS. Papers were included if they met the following criteria: full paper written in the English language; included patients aged ≥ 56 years; were published between 1/1/2009 11/9/2020 and included patients with either suspected or confirmed IMD or infection with N. meningitidis in North America or Europe. Case studies/reports/series were eligible for inclusion if they included persons in the age range of interest. Animal studies and letters to editors were excluded. In addition, the websites of international and national organisations and societies were also checked for relevant information.

RESULTS

There were 5,364 citations identified in total, of which 76 publications were included in this review. We identified that older adults with IMD were mainly affected by serogroups W and Y, which are generally not the predominant strains in circulation in most countries. Older adults had the highest CFRs, probably linked to underlying comorbidities and more atypical presentations hindering appropriate timely management. In addition, there was some evidence of a shift in the incidence of IMD from younger to older adults.

CONCLUSIONS

The use of meningococcal vaccines that include coverage against serogroups W and Y in immunization programs for older adults needs to be evaluated to inform health authorities' decisions of the relative benefits of vaccination and the utility of expanding national immunization programmes to this age group.

Care pathways in invasive meningococcal disease: a retrospective analysis of the French national public health insurance database

Invasive meningococcal disease (IMD) carries a high burden in terms of mortality, long-term complications, and cost, which can be significantly reduced by vaccination. The objectives of this case–control study were to document the care pathways of patients with IMD before, during, and after hospitalization and to assess in-hospital complications and long-term sequelae. Cases consisted of all people hospitalized for IMD in France between 2012 and 2017. Controls were matched by age, gender, and district of residence. Data were extracted from the French national public health insurance database on demographics, hospitalizations, mortality and potential sequelae of IMD. Overall, 3,532 cases and 10,590 controls were assessed and followed up for 2.8 years (median). During hospitalization, 1,577 cases (44.6%) stayed in an intensive care unit, 1,238 (35.1%) required mechanical ventilation, and 43 (1.2%) underwent amputation; 293 cases (8.3%) died in hospital and a further 163 (4.6%) died following discharge; 823 cases (25.4% of survivors) presented ≥1 sequela and 298 (9.2%) presented multiple sequelae. The most frequently documented sequelae were epilepsy (N = 205; 5.8%), anxiety (N = 196; 5.5%), and severe neurological disorders (N = 193; 5.5%). All individual sequelae were significantly more frequent (p < .0001) in cases than controls. Hearing/visual impairment and communication problems were conditions that presented the highest risk for cases compared to controls (risk ratios >20 in all cases). In conclusion, this study highlights the importance of providing optimal medical care for patients with IMD, of minimizing the delay before hospitalization, and of effective prevention through comprehensive vaccination programs.

Benefits of providing optimal medical care for IMD patients.

Importance of minimising the delay before hospitalization.

IMD remains challenging to diagnose, and vaccination is the most efficient way to prevent the disease and its complications.

Neisseria meningitidis IgA1-specific serine protease exhibits novel cleavage activity against IgG3

Neisseria meningitidis (meningococcus) is a common bacterial colonizer of the human nasopharynx but can occasionally cause very severe systemic infections with rapid onset. Meningococci are able to degrade IgA encountered during colonization of mucosal membranes using their IgA1-specific serine protease. During systemic infection, specific IgG can induce complement-mediated lysis of the bacterium. However, meningococcal immune evasion mechanisms in thwarting IgG remain undescribed. In this study, we report for the first time that the meningococcal IgA1-specific serine protease is able to degrade IgG3 in addition to IgA. The IgG3 heavy chain is specifically cleaved in the lower hinge region thereby separating the antigen binding part from its effector binding part. Through molecular characterization, we demonstrate that meningococcal IgA1-specific serine protease of cleavage type 1 degrades both IgG3 and IgA, whereas cleavage type 2 only degrades IgA. Epidemiological analysis of 7581 clinical meningococcal isolates shows a significant higher proportion of cleavage type 1 among isolates from invasive cases compared to carrier cases, regardless of serogroup. Notably, serogroup W cc11 which is an increasing cause of invasive meningococcal disease globally harbors almost exclusively cleavage type 1 protease. Our study also shows an increasing prevalence of meningococcal isolates encoding IgA1P cleavage type 1 compared to cleavage type 2 during the observed decade (2010-2019). Altogether, our work describes a novel mechanism of IgG3 degradation by meningococci and its association to invasive meningococcal disease.

Systematic review of invasive meningococcal disease epidemiology in the Eastern Mediterranean and North Africa region

BACKGROUND

Invasive meningococcal disease (IMD) represents a global health burden. However, its epidemiology in the Eastern Mediterranean (EM) and North Africa (NA) regions is currently not well understood. This review had four key objectives: to describe asymptomatic meningococcal carriage, IMD epidemiology (e.g. serogroup prevalence, case-fatality rates [CFRs]), IMD presentation and management (e.g. clinical diagnosis, antibiotic treatments) and economic impact and evaluation (including health technology assessment [HTA] recommendations) in EM and NA.

METHODS

A systematic literature search (MEDLINE and EMBASE) was conducted (January 2000 to February 2021). Search strings included meningococcal disease and the regions/countries of interest. Identified publications were screened sequentially by title/abstract, followed by screening of the full-text article; articles were also assessed on methodological quality. Literature reviews, genetic sequencing or diagnostic accuracy studies, or other non-pertinent publication type were excluded. An additional grey literature search (non-peer-reviewed sources; start date January 2000) was conducted to the end of April 2019.

RESULTS

Of the 1745 publications identified, 79 were eligible for the final analysis (n = 61 for EM and n = 19 for NA; one study was relevant to both). Asymptomatic meningococcal carriage rates were 0-33% in risk groups (e.g. military personnel, pilgrims) in EM (no data in NA). In terms of epidemiology, serogroups A, B and W were most prevalent in EM compared with serogroups B and C in NA. IMD incidence was 0-20.5/100,000 in EM and 0.1-3.75/100,000 in NA (reported by 7/15 countries in EM and 3/5 countries in NA). CFRs were heterogenous across the EM, ranging from 0 to 57.9%, but were generally lower than 50%. Limited NA data showed a CFR of 0-50%. Data were also limited in terms of IMD presentation and management, particularly relating to clinical diagnosis/antibiotic treatment. No economic evaluation or HTA studies were found.

CONCLUSIONS

High-risk groups remain a significant reservoir of asymptomatic meningococcal carriage. It is probable that inadequacies in national surveillance systems have contributed to the gaps identified. There is consequently a pressing need to improve national surveillance systems in order to estimate the true burden of IMD and guide appropriate prevention and control programmes in these regions.

Evolving strategies for meningococcal vaccination in Europe: Overview and key determinants for current and future considerations

Invasive meningococcal disease (IMD) is a life-threatening, unpredictable condition. Vaccines are available against 5 of the 6 meningococcal serogroups (Men) accounting for nearly all IMD cases worldwide; conjugate monovalent MenC, quadrivalent MenACWY, and protein-based MenB vaccines are commonly used. We provide a comprehensive overview of the evolution of meningococcal vaccination strategies employed in national immunization programmes (NIPs) and their impact on IMD incidence in Europe. A more in-depth description is given for several countries: the United Kingdom (UK), the Netherlands, Greece, Italy, and Ireland. We searched European health authorities' websites and PubMed. Various vaccines and immunization schedules are used in 21 NIPs. Most countries implement MenC vaccination in infants, MenACWY in adolescents, and a growing number, MenB in infants. Only Malta has introduced MenACWY vaccination in infants, and several countries reimburse immunization of toddlers. The UK, Italy, Ireland, Malta, Andorra, and San Marino recommend MenB vaccination in infants and MenACWY vaccination in adolescents, targeting the most prevalent serogroups in the most impacted age groups. Main factors determining new vaccination strategies are fluctuating IMD epidemiology, ease of vaccine implementation, ability to induce herd protection, favorable benefit-risk balance, and acceptable cost-effectiveness. Since 1999, when the UK introduced MenC vaccination, the reduction in IMD incidence has been gradually enhanced as other countries adopted routine meningococcal vaccinations. Meningococcal vaccination strategies in each country are continually adapted to regional epidemiology and national healthcare priorities. Future strategies may include broader coverage vaccines when available (e.g., MenABCWY, MenACWY), depending on prevailing epidemiology.

A novel vaccine to prevent meningococcal disease beyond the first year of life: an early review of MenACYW-TT

INTRODUCTION

Although quadrivalent meningococcal conjugate vaccines have been effective in preventing invasive meningococcal disease (IMD) caused by serogroups A, C, W, and Y across age groups from infants to adults, data on their efficacy and safety in adults ≥56 years of age are lacking. Moreover, multiple available quadrivalent conjugate vaccines require reconstitution prior to administration, introducing the potential for error. A novel quadrivalent meningococcal conjugate vaccine, MenACYW-TT (MenQuadfi®) was approved in 2020 for use in individuals ≥12 months of age as a single dose in the European Union and some other countries and in individuals ≥2 years of age in the United States.

AREAS COVERED

The findings of Phase II/III studies that included >6600 individuals and evaluated the immunogenicity and safety of MenACYW-TT beyond the first year of life are comprehensively summarized and discussed.

EXPERT OPINION

Extensive data on immunogenicity and safety, co-administration with routine vaccines, elicitation of robust booster responses, and significantly higher Men C responses versus monovalent MenC or MenACWY standard-of-care vaccines in toddlers suggest that MenACYW-TT may be suitable for inclusion in National Immunization Programs (NIPs) globally. The authors provide their perspectives on the clinical use of MenACYW-TT across age groups from toddlers through adults.

Incidence of Vaccine-Preventable Childhood Diseases in the European Union and in the European Free Trade Association Countries

Introduction: Despite the widespread availability of vaccines, the incidence of vaccine-preventable childhood diseases (VPCD) started to grow in recent years. The aim of the study was to compare the annual incidence of selected VPCDs in the EU (European Union) and EFTA (European Free Trade Association) countries in the period of the last 5 years (2014–2019 or other intervals, depending on data availability), and the country-specific vaccine schedules. Methods: VPCD incidence rates in Europe were based on “The Surveillance Atlas of Infectious Diseases” by the ECDC (European Centre for Disease Prevention and Control); vaccination schedules were based on ECDC reports. Results: The obligation to vaccinate was not universal, and it generally only applied to two preparations: the MMR (measles, mumps, rubella) vaccine and the one against polio. During the study, the situation associated with mumps did not change or improve in individual countries; the median incidence amounted to 30 cases. The median incidence associated with rubella amounted to 1 case, but in a few countries, it grew very rapidly, i.e., in Germany, Italy, and Romania; in Poland, the incidence was clearly decreasing, from 5923 to 1532 cases. The most dynamic situation concerned measles. The total median was 2.4 cases per 100,000 population; the only one country with falling incidence was Germany. The diseases associated with Streptococcus pneumoniae and Neisseria meningitidis remained at a stable level in all analyzed countries. Conclusion: Vaccine schedules differ among the countries, so does the epidemiological situation of selected diseases. Morbidity on measles was the most disturbing phenomenon: the incidence rate increased in almost 40% of all countries, regardless of the obligation to vaccinate. The increasing incidence of VPCD may be due to anti-vaccine movements, the activity of which is often caused by mistrust and spreading misinformation. In order to better prevent the increase in morbidity, standardization of vaccine schedules and documentation should be considered in the EU countries.

Recent increased incidence of invasive serogroup W meningococcal disease: A retrospective observational study

OBJECTIVES

Neisseria meningitidis serogroup W incidence has increased. Mortality associated with serogroup W has been higher than for other serogroups. Here we report epidemiological characteristics and risks of poor outcomes associated with invasive meningococcal disease in Denmark since 1980.

METHODS

All cases of invasive meningococcal disease reported from 1980-2018 were analyzed. Incidence rates by age, sex, manifestation, and serogroup were calculated. Poisson regression was used to analyze the rise in serogroup W, and multivariate logistic analysis was used to analyze risk factors for mortality.

RESULTS

A total of 5825 cases were analyzed. Risk of serogroup W infection increased after 2015 compared with all previous periods. Younger (<20 years) and older age (≥60 years) was associated with an increased risk of serogroup W infection compared with being aged 20-39. Crude case fatality was 12.0%, 11.9%, 9.2%, and 7.9% for serogroups W, Y, C, and B, respectively. After adjustment for age, sex, and manifestation, 30-day mortality was comparable for serogroups. Older age and manifestation with sepsis independently predicted risk of death.

CONCLUSIONS

Invasive meningococcal disease caused by serogroup W has increased, but serogroup per se was not associated with an increased risk of 30-day mortality.

Clinical manifestations of invasive meningococcal disease in Victoria with the emergence of serogroup W and serogroup Y Neisseria meningitidis

BACKGROUND

Historically, Australian cases of invasive meningococcal disease (IMD) have been most frequently caused by Neisseria meningitidis serogroup B, but recently an increase in cases due to serogroup W (MenW) and serogroup Y (MenY) has occurred.

AIM

To determine whether clinical manifestations of IMD have changed due to increased incidence of MenW and MenY.

METHODS

We performed a retrospective review of IMD cases notified to the Department of Health and Human Services in Victoria, Australia. We compared the period between January 2013 and June 2015 (defined as P1) immediately before the increase in MenW and MenY was noted, with the equal time period of July 2015 to December 2017 (P2), when this increase was observed.

RESULTS

IMD was notified more frequently in P2 than P1 (1.24 vs 0.53 per 100 000 person-years, P < 0.001). IMD cases in P2 were older (46 vs 19 years, P < 0.001), and more likely due to MenW (92/187, 49.2% vs 11/80, 13.8%, P < 0.001) or MenY (31/187, 16.6% vs 4/80, 5.0%, P = 0.01). IMD cases from P2 were more likely bacteraemic (151/187, 80.7% vs 55/80, 68.8%, P = 0.04), while meningitis (68/187, 36.4% vs 41/80, 51.3%, P = 0.03) and rash (65/181, 35.9% vs 45/78, 57.7%, P = 0.002) were less frequent. Intensive care unit admission rates and in-hospital mortality were unchanged.

CONCLUSION

Alongside an increase in IMD in Victoria, the proliferation of cases of MenW and MenY occurred in older patients, and were more often identified through bacteraemia rather than meningitis or purpura fulminans. Clinicians should be aware of these changes to facilitate earlier identification and treatment of IMD.

Atypical presentation of Neisseria meningitidis serogroup W disease is associated with the introduction of the 2013 strain

Since 2015, the incidence of invasive meningococcal disease (IMD) caused by serogroup W (MenW) has increased in Sweden, due to the introduction of the 2013 strain belonging to clonal complex 11. The aim of this study was to describe the clinical presentation of MenW infections, in particular the 2013 strain, including genetic associations. Medical records of confirmed MenW IMD cases in Sweden during the years 1995–2019 (n = 113) were retrospectively reviewed and the clinical data analysed according to strain. Of all MenW patients, bacteraemia without the focus of infection was seen in 44%, bacteraemic pneumonia in 26%, meningitis in 13% and epiglottitis in 8%, gastrointestinal symptoms in 48% and 4% presented with petechiae. Phylogenetic analysis was used for possible links between genetic relationship and clinical picture. The 2013 strain infections, particularly in one cluster, were associated with more severe disease compared with other MenW infections. The patients with 2013 strain infections (n = 68) were older (52 years vs. 25 years for other strains), presented more often with diarrhoea as an atypical presentation (P = 0.045) and were more frequently admitted for intensive care (P = 0.032). There is a risk that the atypical clinical presentation of MenW infections, with predominantly gastrointestinal or respiratory symptoms rather than neck stiffness or petechiae, may lead to delay in life-saving treatment.