Cost-effectiveness analysis of vaccination strategies against meningococcal disease for children under nine years of age in China

Meningococcal vaccination strategies in China are intricate, including multiple vaccines targeting different serogroups. The current National Immunization Program (NIP) includes two polysaccharide vaccines for serogroups A and C (MPV-A and MPV-AC), covering limited serogroups and requiring adaptation. This study aims to evaluate the cost-effectiveness of replacing the current strategy with alternative strategies utilizing non-NIP vaccines to inform policy decisions. From a societal perspective, a decision tree-Markov model was constructed to simulate the economic and health consequences of meningococcal disease in a 2019 birth cohort with four vaccination strategies. Epidemiology, vaccine efficacy, cost, and other parameters were derived from previous studies. We conducted sensitivity analyses to assess the robustness of the findings and explored prices for non-NIP vaccines that enable cost-effective strategies. Compared to the current strategy, alternative strategies using quadrivalent polysaccharide vaccine (MPV-4), bivalent conjugate vaccine (MCV-AC), and quadrivalent conjugate vaccine (MCV-4) could avoid 91, 286, and 455 more meningococcal cases. The ICERs were estimated at approximately $250 thousand/QALY, $450 thousand/QALY, and $1.5 million/QALY, all exceeding the threshold of three times GDP per capita. The alternative strategies were not cost-effective. However, if vaccine prices were reduced to $3.9 for MPV-4, $9.9 for MCV-AC, and $12 for MCV-4, the corresponding strategy would be cost-effective. The current meningococcal vaccination strategy in China could effectively prevent the disease at a low cost, but with limited serogroup coverage. Strategies using MPV-4, MCV-AC, or MCV-4 could increase health benefits at a substantial cost, and might become cost-effective if vaccine prices decrease.

Meningococcal disease in the Middle East: A report from the Global Meningococcal Initiative

This review details recent findings from the Global Meningococcal Initiative's (GMI) recent meeting on the surveillance and control strategies for invasive meningococcal disease in the Middle East. The nature of case reporting and notification varies across the region, with many countries using bacterial meningitis as an IMD case definition in lieu of meningitis and septicaemia. This may overlook a significant burden associated with IMD leading to underreporting or misreporting of the disease. Based on these current definitions, IMD reported incidence remains low across the region, with historical outbreaks mainly occurring due to the Hajj and Umrah mass gatherings. The use of case confirmation techniques also varies in Middle Eastern countries. While typical microbiological techniques, such as culture and Gram staining, are widely used for characterisation, polymerase chain reaction (PCR) testing is utilised in a small number of countries. PCR testing may be inaccessible for several reasons including sample transportation, cost, or a lack of laboratory expertise. These barriers, not exclusive to PCR use, may impact surveillance systems more broadly. Another concern throughout the region is potentially widespread ciprofloxacin resistance since its use for chemoprophylaxis remains high in many countries.

The Diverse Spectrum of Invasive Meningococcal Disease in Pediatric and Adolescent Patients: Narrative Review of Cases and Case Series

INTRODUCTION

Invasive meningococcal disease (IMD) is a potentially life-threatening disease caused by Neisseria meningitidis infection. We reviewed case reports of IMD from newborns, infants, children, and adolescents, and described the real-life clinical presentations, diagnoses, treatment paradigms, and clinical outcomes.

METHODS

PubMed and Embase were searched for IMD case reports on patients aged ≤ 19 years published from January 2011 to March 2023 (search terms "Neisseria meningitidis" or "invasive meningococcal disease", and "infant", "children", "paediatric", pediatric", or "adolescent").

RESULTS

We identified 97 publications reporting 184 cases of IMD, including 25 cases with a fatal outcome. Most cases were in adolescents aged 13-19 years (34.2%), followed by children aged 1-5 years (27.6%), children aged 6-12 years (17.1%), infants aged 1-12 months (17.1%), and neonates (3.9%). The most common disease-causing serogroups were W (40.2%), B (31.7%), and C (10.4%). Serogroup W was the most common serogroup in adolescents (17.2%), and serogroup B was the most common in the other age groups, including children aged 1-5 years (11.5%). The most common clinical presentations were meningitis (46.6%) and sepsis (36.8%).

CONCLUSIONS

IMD continues to pose a threat to the health of children and adolescents. While this review was limited to case reports and is not reflective of global epidemiology, adolescents represented the largest group with IMD. Additionally, nearly half of the patients who died were adolescents, emphasizing the importance of monitoring and vaccination in this age group. Different infecting serogroups were predominant in different age groups, highlighting the usefulness of multivalent vaccines to provide the broadest possible protection against IMD. Overall, this review provides useful insights into real-life clinical presentations, treatment paradigms, diagnoses, and clinical outcomes to help clinicians diagnose, treat, and, ultimately, protect patients from this devastating disease.

Risk Factors for Serogroup B Meningococcal Disease Among College Students

Background

College students are at increased risk for invasive meningococcal disease, but which students are most at risk is unclear.

Methods

US meningococcal disease cases in persons aged 18-24 years during 2014-2017 were included. Patients were classified as undergraduate students or other persons. Incidence in different student and non-student populations was compared.

Results

During 2014-2017, 229 meningococcal disease cases were reported in persons aged 18-24 years; 120 were in undergraduate students. Serogroup B accounted for 74% of cases in students. Serogroup B disease incidence was 4-fold higher in undergraduate students, 11.8-fold higher among first-year undergraduate students, and 8.6-fold higher among residence hall residents versus non-undergraduates. During outbreaks, students affiliated with Greek life had a 9.8-fold higher risk of disease compared to other students. A significantly higher party school ranking was observed for schools with sporadic or outbreak cases when compared to schools with no cases.

Conclusions

The findings of increased disease risk among first-year students and those living on campus or affiliated with Greek life can inform shared clinical decision-making for serogroup B vaccines to prevent this rare but serious disease. These data also can inform school serogroup B vaccination policies and outbreak response measures.

Informing the use of a supplementary immunisation programme for the management of a community cluster of invasive meningococcal disease, Yorkshire, 2022

OBJECTIVES

To outline the management of a community cluster of serogroup B invasive meningococcal disease (IMD) cases, including key factors for decision making and the choice and implementation of control measures.

STUDY DESIGN

Descriptive report of cluster management.

METHODS

Subtyping of IMD cases identified a number of potentially linked cases in a defined geographical area. An Incident Management Team (IMT) was convened to coordinate the public health response. A case definition was developed in order to identify further cases within the cluster.

RESULTS

Four cases of IMD met the case definition and were initially considered as part of this cluster. Three resided in the same small town, which was the focus for public health management. The IMT agreed that it would be proportionate to instigate additional control measures. The population at higher risk of infection were identified, and a supplementary vaccination programme was rolled out in the community. Over five clinics, 45.6% (639/1401) of the target cohort received at least one dose of the vaccine, with 34.7% (486/1401) receiving both doses. Inequalities in uptake were observed by sex, age and deprivation.

CONCLUSIONS

Decision making for public health responses to IMD clusters is complex. Informed by epidemiological evidence, numerous partners engaged in collaborative decision making, which was critical for the effective implementation of the community response. Links between the local authority public health team and the community enabled the use of existing structures and relationships to maximise the number of vaccinations delivered. No further cases of IMD linked to this cluster were identified.

Meningococcal B Immunisation in Adults and Potential Broader Immunisation Strategies: A Narrative Review

Recombinant vaccines against invasive meningococcal disease due to Neisseria meningitidis serogroup B (MenB) have shown substantial impact in reducing MenB disease in targeted populations. 4CMenB targets four key N. meningitidis protein antigens; human factor H binding protein (fHbp), Neisserial heparin binding antigen (NHBA), Neisseria adhesin A (NadA) and the porin A protein (PorA P1.4), with one or more of these expressed by most pathogenic MenB strains, while MenB-FHbp targets two distinct fHbp variants. While many countries recommend MenB immunisation in adults considered at high risk due to underlying medical conditions or immunosuppression, there are no recommendations for routine use in the general adult population. We reviewed the burden of MenB in adults, where, while incidence rates remain low (and far lower than in young children < 5 years of age at greatest risk), a substantial proportion of MenB cases (20% or more) is now observed in the adult population; evident in Europe, Australia, and in the United States. We also reviewed immunogenicity data in adults from clinical studies conducted during MenB vaccine development and subsequent post-licensure studies. A 2-dose schedule of 4CMenB generates hSBA titres ≥ 1:4 towards all four key vaccine target antigens in up to 98-100% of subjects. For MenB-FHbp, a ≥ fourfold rise in hSBA titres against the four primary representative test strains was observed in 70-95% of recipients following a 3-dose schedule. While this suggests potential benefits for MenB immunisation if used in adult populations, data are limited (especially for adults > 50 years) and key aspects relating to duration of protection remain unclear. Although a broader adult MenB immunisation policy could provide greater protection of the adult population, additional data are required to support policy decision-making.

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.

Carriage of Neisseria meningitidis among travelers attending the Hajj pilgrimage, circulating serogroups, sequence types and antimicrobial susceptibility: A multinational longitudinal cohort study

BACKGROUND

Travel to international mass gatherings such as the Hajj pilgrimage increases the risk of Neisseria meningitidis transmission and meningococcal disease. We investigated carriage and acquisition of N. meningitidis among travelers to Hajj and determined circulating serogroups, sequence types and antibiotic susceptibility among isolates.

METHOD

We conducted a multinational longitudinal cohort study among 3921 traveling pilgrims in two phases: Pre-Hajj and Post-Hajj. For each participant, a questionnaire was administered and an oropharyngeal swab was obtained. N. meningitidis was isolated, serogrouped, and subjected to whole genome sequence analysis and antibiotic susceptibility testing.

RESULTS

Overall carriage and acquisition rates of N. meningitidis were 0.74% (95%CI: 0.55-0.93) and 1.10% (95%CI: 0.77-1.42) respectively. Carriage was significantly higher Post-Hajj (0.38% vs 1.10%, p = 0.0004). All isolates were nongroupable, and most belonged to the ST-175 complex and were resistant to ciprofloxacin with reduced susceptibility to penicillins. Three potentially invasive isolates (all genogroup B) were identified in the Pre-Hajj samples. No factors were associated with Pre-Hajj carriage. Suffering influenza like illness symptoms and sharing a room with >15 people were associated with lower carriage Post-Hajj (adjOR = 0.23; p = 0.008 and adjOR = 0.27; p = 0.003, respectively).

CONCLUSION

Carriage of N. meningitidis among traveler to attending Hajj was low. However, most isolates were resistant to ciprofloxacin used for chemoprophylaxis. A review of the current meningococcal disease preventive measures for Hajj is warranted.

Pediatric Invasive Meningococcal Disease, Auckland, New Zealand (Aotearoa), 2004-2020

New Zealand (Aotearoa) experienced a Neisseria meningitidis serogroup B epidemic during 1991-2006, and incidence remains twice that of other high-income countries. We reviewed clinical, laboratory, and immunization data for children <15 years of age with laboratory-confirmed invasive meningococcal disease in Auckland, New Zealand, during January 1, 2004-December 31, 2020. Of 319 cases in 318 children, 4.1% died, and 23.6% with follow-up data experienced sequelae. Children of Māori and Pacific ethnicity and those living in the most deprived areas were overrepresented. Eighty-one percent were positive for N. meningitidis serogroup B, 8.6% for serogroup W, 6.3% for serogroup C, and 3.7% for serogroup Y. Seventy-nine percent had bacteremia, and 63.9% had meningitis. In New Zealand, Māori and Pacific children are disproportionately affected by this preventable disease. N. meningitidis serogroup B vaccine should be included in the New Zealand National Immunization Schedule to address this persistent health inequity.

Review of the epidemiology, diagnosis and management of invasive meningococcal disease in Vietnam

Invasive meningococcal disease (IMD), caused by Neisseria meningitidis, is life-threatening with a high case fatality rate (CFR) and severe sequelae. We compiled and critically discussed the evidence on IMD epidemiology, antibiotic resistance and disease management in Vietnam, focusing on children. PubMed, Embase and gray literature searches for English, Vietnamese and French publications, with no date restrictions, retrieved 11 eligible studies. IMD incidence rate (/100,000 population) was 7.4 [95% confidence interval 3.6-15.3] in children under 5 years of age; driven by high rates in infants (e.g. 29.1 [8.0-106.0] in 7-11 month-olds). Serogroup B IMD was predominant. Neisseria meningitidis strains may have developed resistance to streptomycin, sulfonamides, ciprofloxacin, and possibly ceftriaxone. There was a lack of current data on diagnosis and treatment of IMD, which remain challenging. Healthcare professionals should be trained to rapidly recognize and treat IMD. Preventive measures, such as routine vaccination, could help address the medical need.

Meningococcal A conjugate vaccine coverage in the meningitis belt of Africa from 2010 to 2021: a modelling study

BACKGROUND

As of the end of 2021, twenty-four countries in the African meningitis belt have rolled out mass campaigns of MenAfriVac®, a meningococcal A conjugate vaccine (MACV) first introduced in 2010. Twelve have completed introduction of MACV into routine immunisation (RI) schedules. Although select post-campaign coverage data are published, no study currently comprehensively estimates MACV coverage from both routine and campaign sources in the meningitis belt across age, country, and time.

METHODS

In this modelling study, we assembled campaign data from the twenty-four countries that had introduced any immunisation activity during or before the year 2021 (Benin, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Côte d'Ivoire, Democratic Republic of the Congo, Ethiopia, Eritrea, the Gambia, Ghana, Guinea, Guinea Bissau, Kenya, Mali, Mauritania, Niger, Nigeria, Senegal, South Sudan, Sudan, Togo and Uganda) via WHO reports and RI data via systematic review. Next, we modelled RI coverage using Spatiotemporal Gaussian Process Regression. Then, we synthesized these estimates with campaign data into a cohort model, tracking coverage for each age cohort from age 1 to 29 years over time for each country.

FINDINGS

Coverage in high-risk locations amongst children aged 1-4 in 2021 was estimated to be highest in Togo with 96.0% (95% uncertainty interval [UI] 92.0-99.0), followed by Niger with 87.2% (95% UI 85.3-89.0) and Burkina Faso, with 86.4% (95% UI 85.1-87.6). These countries had high coverage values driven by an initial successful mass immunisation campaign, followed by a catch-up campaign, followed by introduction of RI. Due to the influence of older mass vaccination campaigns, coverage proportions skewed higher in the 1-29 age group than the 1-4 group, with a median coverage of 82.9% in 2021 in the broader age group compared to 45.6% in the narrower age group.

INTERPRETATION

These estimates highlight where gaps in immunisation remain and emphasise the need for broader efforts to strengthen RI systems. This methodological framework can be applied to estimate coverage for any vaccine that has been delivered in both routine and supplemental immunisation activities.

FUNDING

Bill and Melinda Gates Foundation.

A phase 3, randomized, controlled, open-label study to evaluate the persistence up to 5 years of 1 or 2 doses of meningococcal conjugate vaccine MenACWY-TT given with or without 13-valent pneumococcal conjugate vaccine in 12-14-month-old children

BACKGROUND

Immunogenicity and safety up to 5 years after administration of 1 or 2 doses of quadrivalent meningococcal serogroup A, C, W, and Y tetanus toxoid conjugate vaccine (MenACWY-TT) given alone or with 13-valent pneumococcal conjugate vaccine (PCV13) in children was investigated.

METHODS

This phase 3 study randomized healthy 12-24-month-olds to MenACWY-TT at Month 0 (ACWY1d), MenACWY-TT at Months 0 and 2 (ACWY2d), MenACWY-TT and PCV13 at Month 0 (Co-Ad), or PCV13 at Month 0 and MenACWY-TT at Month 2 (PCV13/ACWY). Immune responses 1, 3, and 5 years after primary vaccination were evaluated with serum bactericidal activity using rabbit complement (rSBA) titers ≥ 1:8 and geometric mean titers (GMTs). Evaluation of serious adverse events up to 5 years after primary vaccination are reported.

RESULTS

Of the 802 children randomized in the study, 619 completed the study through Year 5. Immune responses after vaccination declined over time but were higher 5 years after vaccination compared with levels before vaccination. At Year 5, the percentages of children with rSBA titers ≥ 1:8 across all serogroups were 20.5 %-58.6 %, 28.4 %-65.8 %, 23.9 %-52.8 %, and 19.4 %-55.8 % in the ACWY1d, ACWY2d, Co-Ad, and PCV13/ACWY groups, respectively. Comparable antibody persistence at Year 5 was observed for participants receiving 1 or 2 doses of MenACWY-TT, although GMTs were elevated in those who received 2 versus 1 dose. The percentage of children with protective antibody titers at Year 5 was similar in participants who received PCV13 and MenACWY-TT compared with that observed for participants who only received 1 or 2 MenACWY-TT doses. No new safety concerns were identified during the study period.

CONCLUSION

Antibody responses persisted in the majority of children up to 5 years after primary vaccination with MenACWY-TT administered in a 1- or 2-dose regimen with or without PCV13, with no new safety concerns identified.

CLINICALTRIALS

gov Identifier NCT01939158; EudraCT number 2013-001083-28.

Societal Preferences for Meningococcal B Vaccination in Children: A Discrete Choice Experiment in Spain

INTRODUCTION

Immunization is the most effective strategy for the prevention of invasive meningococcal disease caused by Neisseria meningitidis serogroup B (MenB); however, parents need to weigh the risk-benefit and financial impact of immunizing their children against MenB in the absence of a national immunization program (NIP). This study aimed to explore societal preferences (of parents and pediatricians) regarding the attributes of a MenB vaccine in Spain.

METHODS

A discrete choice experiment (DCE) based on cross-sectional surveys was carried out to determine preferences. A literature review and scientific committee determined the six attributes related to the MenB vaccine included in the DCE: vaccination age, cost, duration, percentage of protection, adverse events probability, and expert/authority recommendation. Data were analyzed using a mixed logit model. Relative importance (RI) of attributes was calculated and compared between parents and pediatricians.

RESULTS

A total of 278 parents [55.8% female, mean age 40.4 (standard deviation, SD 7.3) years] and 200 pediatricians [73.0% female, mean age 45.8 (SD 12.9) years] answered the DCE. For parents, the highest RI was attributed to vaccine cost, expert/authority recommendation, and percentage of protection (26.4%, 26.1%, and 22.9%, respectively), while for pediatricians the highest RI was assigned to percentage of protection, expert/authority recommendation, and vaccination age (27.2%, 23.7%, and 22.6%, respectively). Significant differences between parents and pediatricians were found in the RI assigned to all attributes (p < 0.001), except for vaccine recommendation.

CONCLUSION

In the decision regarding MenB vaccination, cost was a driver in parental decision-making but had a low RI for pediatricians and, conversely, vaccination age was highly valued by pediatricians but was the attribute with least importance for parents. Despite these differences, expert/authority recommendation and percentage of protection were essential criteria for both groups. These results provide relevant information about MenB vaccination, highlighting the importance of considering societal preferences for NIP inclusion.

Primary septic arthritis of the knee caused by Neisseria meningitidis serogroup B in an elderly patient. Case report and review of the literature

PURPOSE

Primary meningococcal arthritis (PMA) represents an uncommon clinical presentation of meningococcal infection, mainly reported among young people. Herein, a case of PMA of the knee in an elderly patient is described.

CASE PRESENTATION

On January 2022, an 87-year-old patient arrived at hospital with continuous fever persisting for three days and a picture of pain, swelling, redness, and warmth of her left knee. An arthrocentesis was promptly performed and the inoculated synovial fluid turned positive with numerous Gram-negative diplococci at the microscopic examination. The identification of bacteria was done in 48 h using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) MS systems (VITEK^®MS-bioMérieux) and standard microbiological procedures (VITEK^®2 NH ID card-bioMérieux). Both methods identified the strain as N. meningitidis. The meningococcal isolate belonged to the serogroup B (MenB), Sequence type (ST)-162/clonal complex (cc)162. Two grams of ceftriaxone twice a day were administered for 21 days; than cefditoren pivoxil 400 mg twice a day for further 6 weeks after discharge. In Italy, from 2018 to January 2022, among 135 MenB, 31 MenB/cc162 were identified, of which only the case here reported was associated with an atypical clinical presentation.

REVIEW OF THE LITERATURE

A total of 41 cases of PMA caused by N. meningitidis was reported in the literature, but only four occurred in elderly. To our knowledgements, no cases of PMA caused by MenB were previously reported among patients of more than 65 years of age.

Variation in CFHR3 determines susceptibility to meningococcal disease by controlling factor H concentrations

Neisseria meningitidis protects itself from complement-mediated killing by binding complement factor H (FH). Previous studies associated susceptibility to meningococcal disease (MD) with variation in CFH, but the causal variants and underlying mechanism remained unknown. Here we attempted to define the association more accurately by sequencing the CFH-CFHR locus and imputing missing genotypes in previously obtained GWAS datasets of MD-affected individuals of European ancestry and matched controls. We identified a CFHR3 SNP that provides protection from MD (rs75703017, p value = 1.1 × 10^-16) by decreasing the concentration of FH in the blood (p value = 1.4 × 10^-11). We subsequently used dual-luciferase studies and CRISPR gene editing to establish that deletion of rs75703017 increased FH expression in hepatocyte by preventing promotor inhibition. Our data suggest that reduced concentrations of FH in the blood confer protection from MD; with reduced access to FH, N. meningitidis is less able to shield itself from complement-mediated killing.

High-Resolution Melting (HRM) for rapid MLST analysis of Neisseria meningitidis

The genetic characterization of meningococcal isolates is extremely important for the epidemiological monitoring of meningococcal disease, through the identification of circulating epidemic clones, with the purpose of supporting specific actions of Health Surveillance to contain outbreaks. The objective of this work is to determine a strategy for the epidemiological control of Neisseria meningitidis (Nm) through the detection of genetic signatures of Multilocus Sequence Typing (MLST) genes, by the method of high-resolution DNA melting analysis (qPCR-HRM), to identify the main hypervirulent clones circulating in the country. We analyzed 65 cc103 strains, 19 cc11, 38 cc32 and 8 cc41/44 and 17 were not associated to a specific cc. For the abcZ gene a total of 112 strains were tested, 79 for adk and gdh genes, 87 for aroE, 27 for fumC and 70 strains for pdhC gene. The results obtained were compared and validated with nucleotide sequencing. The percentage of correct allele detection for each clonal complex ranged between 77% and 100%. After an active search in PubMLST, it was found that by inserting results from at least 4 alleles in the MLST database, it is possible to determine the clonal complex of 99% to 100% of the deposited samples. The results obtained in this study suggest that it is possible to identify Nm clonal complexes by a combination analysis of melting curves (TM) of four constitutional genes included in the MLST scheme by qPCR-HRM.

Inclusion of a dual signal sequence enhances the immunogenicity of a novel viral vectored vaccine against the capsular group B meningococcus

BACKGROUND

Disease caused by the capsular group B meningococcus (MenB) is the leading cause of infectious death in UK infants. A novel adenovirus-based vaccine encoding the MenB factor H binding protein (fHbp) with an N-terminal dual signal sequence induces high titres of protective antibody after a single dose in mice. A panel of N-terminal signal sequence variants were created to assess the contribution of components of this sequence to transgene expression kinetics of the encoded antigen from mammalian cells and the resultant effect on immunogenicity of fHbp.

RESULTS

The full-length signal sequence (FL SS) resulted in superior early antigen expression compared with the panel of variants, as measured by flow cytometry and confocal imaging, and supported higher bactericidal antibody levels against the expressed antigen in mouse sera < 6 weeks post-immunisation than the licensed four component MenB vaccine. The FL SS also significantly increased antigen-specific T cell responses against other adenovirus-encoded bacterial antigens in mice.

CONCLUSIONS

These findings demonstrate that the FL SS enhances immunogenicity of the encoded antigen, supporting its inclusion in other viral vectored bacterial antigen transgenes.

Psychosocial and organizational barriers and facilitators of meningococcal vaccination (MenACWY) acceptance among adolescents and parents during the Covid-19 pandemic: a cross-sectional survey

BACKGROUND

This study aimed to identify differences and similarities among adolescents and parents in various psychosocial factors influencing meningococcal ACWY (MenACWY) vaccination acceptance. Besides, the impact of the Covid-19 pandemic was assessed as well as resulting organizational adjustments.

METHODS

We conducted a cross-sectional survey among adolescents that attended the appointment for the MenACWY vaccination in South Limburg between May and June 2020, and their parents. Independent t-tests and χ² test were performed to explore differences in psychosocial and organisational factors between adolescents and parents.

RESULTS

In total, 592 adolescents (20%) and 1197 parents (38%) filled out the questionnaire. Adolescents scored lower on anticipated negative affect towards MenACWY vaccination refusal [t (985.688) = - 9.32; ρ < 0.001], moral norm towards MenACWY vaccination acceptance [t (942.079) = - 10.38; ρ < 0.001] and knowledge about the MenACWY vaccination and meningococcal disease [t (1059.710) = - 11.24; ρ < 0.001]. Both adolescents and parents reported a social norm favouring accepting childhood vaccinations, but adolescent scored higher [t (1122.846) = 23.10; ρ < 0.001]. The Covid-19 pandemic did barely influence the decision to accept the MenACWY vaccination. Only 6% of the participants indicated that Covid-19 influenced their decision. In addition, the individual vaccination appointment was rated very positive. Most adolescents (71.5%) and parents (80.6%) prefer future vaccinations to be offered individually rather than having mass vaccinations sessions.

CONCLUSIONS

This study provides an indication of which psychosocial and organisational factors should be addressed in future MenACWY vaccination campaigns. Individual vaccination appointments for adolescents should be considered, taking the costs and logistical barriers into account.

Meningococcal Disease and Immunization Activities in Hajj and Umrah Pilgrimage: a review

Invasive meningococcal disease (IMD) outbreaks associated with Hajj and Umrah pilgrimage events in the Kingdom of Saudi Arabia (KSA) are well recognized. Past outbreaks have been associated with substantial intercontinental spread of specific Neisseria meningitidis serogroups. The emergence of meningococcal serogroup W (MenW) was a global concern following the 2000/2001 Hajj outbreaks. Broader compulsory meningococcal serogroups A, C, W and Y (MenACWY) immunization strategies for pilgrims were introduced in response to these events and led to substantial declines in IMD cases associated with these mass gatherings. However, there remains potential for future outbreaks either within KSA during the Hajj or in local populations via pilgrim meningococcal transmission on their return. While the annual Hajj involves pilgrims from over 185 countries, two-thirds of these arrive from 13 countries, chiefly from across South-East Asia, the Middle East and North African (MENA) regions; for which we review the relevant epidemiology of IMD and meningococcal carriage. While disease surveillance is limited and data are often lacking, MenB is an important serogroup associated with IMD and carriage in a number of countries. Available literature suggests that most pilgrims receive polysaccharide MenACWY vaccines (which do not impact carriage and onward transmission) and incomplete compliance with visa/entry immunization regulations is reported. Existing preventative approaches for visiting pilgrims require continued oversight. More complete compliance and switching to the conjugated MenACWY vaccine can provide more robust and broader protection for pilgrims. Additional immunization options could also be considered.

Viral vectors expressing group B meningococcal outer membrane proteins induce strong antibody responses but fail to induce functional bactericidal activity

OBJECTIVE

Adenoviral vectored vaccines, with the appropriate gene insert, induce cellular and antibody responses against viruses, parasites and intracellular pathogens such as Mycobacterium tuberculosis. Here we explored their capacity to induce functional antibody responses to meningococcal transmembrane outer membrane proteins.

METHODS

Vectors expressing porin A and ferric enterobactin receptor A antigens were generated, and their immunogenicity assessed in mice using binding and bactericidal assays.

RESULTS

The viral vectors expressed the bacterial proteins in an in vitro cell-infection assay and, after immunisation of mice, induced higher titres (>10⁵ end-point titre) and longer lasting (>32 weeks) transgene-specific antibody responses in vivo than did outer membrane vesicles containing the same antigens. However, bactericidal antibodies, which are the primary surrogate of protection against meningococcus, were undetectable, despite different designs to support the presentation of the protective B-cell epitopes.

CONCLUSION

These results demonstrate that, while the transmembrane bacterial proteins expressed by the viral vector induced strong and persistent antigen-specific antibodies, this platform failed to induce bactericidal antibodies. The results suggest that conformation or post-translational modifications of bacterial outer membrane antigens produced in eukaryote cells might not result in presentation of the necessary epitopes for induction of functional antibodies.

Dynamics in public perceptions and media coverage during an ongoing outbreak of meningococcal W disease in the Netherlands

Background

From 2015 to 2018, the Netherlands faced an outbreak of invasive meningococcal disease (IMD) caused by serogroup W. To counter the rise in infections, the government introduced a catch-up menACWY vaccination campaign for teenagers in 2018 and 2019. The outbreak situation induced substantial media attention and a run on menACWY vaccines outside the vaccination campaign. This study aimed to gain insights into the dynamics of public perceptions of and responses to the outbreak and the menACWY vaccination, and into the media coverage about the outbreak.

Methods

Three repeated surveys (N = 1110) between 2017 and 2019 were sent to parents of teenagers invited for a menACWY catch-up vaccination, other parents, and individuals with no under-age children. These surveys assessed IMD risk perceptions, attitudes towards the menACWY vaccination, trust in involved institutions, and willingness to vaccinate with the menACWY vaccine. Changes in the public perceptions and responses were studied with linear multilevel regression analyses. In addition, 103 national newspaper articles from the period 2017–2019 were thematically coded with themes about IMD and the menACWY vaccination.

Results

The survey results showed clear increases in perceived IMD severity, positive attitude towards the menACWY vaccination, and willingness to vaccinate over time. Perceived IMD vulnerability remained low across all three waves, and trust in involved institutions increased slightly. Differences between the survey groups were limited. The newspaper articles discussed the rise in infections extensively, the disease symptoms, and the possible fatal outcome of IMD. In addition, while many articles discussed the menACWY vaccine shortage, few discussed the safety or effectiveness of the vaccine.

Conclusion

The real-time insights into the interrelated dynamics of public perceptions, responses, and media coverage provide an integrated portrait of the social developments during this outbreak. The focus on IMD severity and the absence of doubt in the public discussion about vaccine safety may have played an important role in the societal response to this outbreak and the recommended vaccine.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12920-8.

Validity of university students' self-reported vaccination status after a meningococcal B outbreak

After an outbreak of meningococcal B (MenB) disease at a university, we surveyed students regarding their vaccination status 2 months and 20 months after campus-led vaccination campaigns and compared students' self-report to vaccination records. Nearly all participants accurately reported the number of vaccine doses at both visits. Among those who received two doses of the vaccine, accurate recall of the timing of MenB vaccination was 85.7% (95% CI: 82.7-88.6) in the short term and 62.9% (95% CI: 56.0-69.8) in the long term. After the outbreak, only one-third reported feeling 'very confident' in their MenB disease and vaccine knowledge. Our findings suggest that the validity of self-reported vaccination status among university students in an outbreak setting is high, but that if the duration of protection is unknown and additional doses of vaccine may be needed, documented vaccination records may be preferred over self-report to assess timing of vaccine receipt.

Epidemiology of invasive meningococcal disease and sequelae in the United Kingdom during the period 2008 to 2017 - a secondary database analysis

Background

Invasive meningococcal disease (IMD) causes high fatality in untreated patients alongside long-term sequelae in 20% survivors. For a comprehensive assessment of epidemiology, an analysis of these sequelae is required. This study aims to investigate the epidemiology of disease between 2008 and 2017 including a description of the sequelae, through the analysis of data collected from the UK Clinical Practice Research Datalink (CPRD) linked with data from the Hospital Episode Statistics (HES), and Office for National Statistics (ONS) mortality registry data.

Methods

This was a 10-year retrospective observational cohort study designed to describe the incidence, case-fatality rate (CFR) and occurrence of sequelae due to meningococcal disease, in the UK between 2007 and 2017 using data from the UK CPRD-HES-ONS. Cases were identified and matched on age, gender, date of diagnosis of IMD and followed-up-time with a control group without IMD. Demographics, clinical characteristics, mortality, and IMD-related sequelae were examined for IMD cases and compared with matched controls for a more comprehensive assessment.

Results

The study analysed 640 IMD patients with majority of the cases diagnosed (76.9%) in a hospital setting. Age-group analysis showed a decrease in the incidence rate of IMD in patients aged <1 year (30.4 – 7.5%) and an increase in those >50 years (10.4 – 27.8%). CFR was slightly higher among females, toddlers, and adults >50 years. No significant change in CFR was observed over study period. Case-control study showed a higher number of IMD sequelae among cases compared to age- and gender-matched controls, especially in those ≥ 50 years.

Conclusion

The study showed that, despite a relatively low incidence rate, IMD is responsible for a high CFR, namely in older age groups and by a high number of IMD sequelae. The study showed that leveraging data from existing databases can be used to complement surveillance data in truly assessing the epidemiology of IMD. Despite the availability of routine vaccination programs, IMD still poses a significant burden in the healthcare system of the UK. Optimization of vaccination programs may be required to reduce the disease burden.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-12933-3.

Timing of meningococcal vaccination with 4CMenB (Bexsero®) in children with invasive meningococcal group B (MenB) disease in England

BACKGROUND

Timely vaccination is critical for providing early protection against meningococcal B (MenB) disease because of the high incidence in early childhood. We assessed the timeliness of vaccination in children with confirmed MenB disease after 4CMenB (a recombinant protein-based vaccine) implementation into the national infant immunisation programme in England.

METHODS

Public Health England (PHE) conducts surveillance of invasive meningococcal disease (IMD) in England. Children born since 01 July 2015 who developed MenB disease between 01 September 2015 and 31 August 2019 (four surveillance years) were included in the analysis.

RESULTS

There were 276 children with laboratory-confirmed MenB disease, including 36 infants who were too young for vaccination, 59 who were eligible for one 4CMenB dose, 104 for two doses and 77 for 3 doses before they developed MenB disease. Prior to developing MenB disease, there were 59 opportunities for vaccination with two 4CMenB doses in 48/104 (46.5%) eligible infants and 41 opportunities in 28/77 (36.6%) children aged ≥ 1 year who were under-immunised. A schedule with a shorter interval at 8 and 12 weeks of age, compared to the current schedule at 8 and 16 weeks, had the potential to offer an additional 4CMenB dose to 35/58 infants (58.6%) who developed MenB disease between 10 and 18 weeks of age.

CONCLUSIONS

A high proportion of infants and toddlers with laboratory-confirmed MenB disease had not received their scheduled 4CMenB vaccine prior to developing MenB disease. An infant priming schedule with a shorter interval of 4 weeks has the potential to provide earlier protection against MenB disease.

Serogroup A, C, W, and Y meningococcal disease in persons previously vaccinated with a serogroup ACWY meningococcal vaccine - United States, 2014-2018

BACKGROUND

The Advisory Committee on Immunization Practices (ACIP) recommends routine vaccination with a quadrivalent meningococcal conjugate serogroup A,C,W,Y (MenACWY) vaccine at 11-12 years of age, with a booster dose at 16 years. ACIP also recommends meningococcal vaccination for persons at increased risk of meningococcal disease, including a 2-dose primary series and regular booster doses for persons at increased risk because of underlying medical conditions. U.S. cases of serogroup A, C, W, and Y meningococcal disease in persons previously vaccinated with MenACWY vaccine have not been systematically described since 2008. Characterization of these cases is important to understand potential factors leading to breakthrough disease.

METHODS

We analyzed cases of serogroup A,C,W, and Y meningococcal disease reported through the National Notifiable Diseases Surveillance System (NNDSS) from 2014 through 2018. State health departments submitted additional information on risk factors and clinical course.

RESULTS

During 2014-2018, 822 cases of serogroup A, C, W, and Y meningococcal disease were reported through NNDSS; 34 (4%) were in patients who previously received ≥ 1 dose of MenACWY vaccine. Twenty-three vaccinated patients were up-to-date on MenACWY vaccine per recommendations, and seven were not up-to-date; four were missing information on the number of doses received. Seventeen cases (50%) occurred > 3 years after the most recent dose. A significantly higher proportion of vaccinated patients were people living with HIV (PLWH) compared to unvaccinated patients. Eight of the 34 vaccinated patients were immunosuppressed, including five PLWH, one taking eculizumab, and two taking other immunosuppressive medications. The case fatality ratio did not differ between vaccinated and unvaccinated patients.

CONCLUSIONS

Immunosuppression, incomplete vaccination, and waning immunity likely contributed to breakthrough cases of meningococcal disease among people who received MenACWY vaccine. Continued monitoring of serogroup A, C, W, and Y meningococcal disease in previously vaccinated persons will help inform meningococcal disease prevention efforts.

Public Health Impact and Cost-Effectiveness Analysis of Routine Infant 4CMenB Vaccination in Germany to Prevent Serogroup B Invasive Meningococcal Disease

Introduction

Invasive meningococcal disease (IMD) is an uncommon, severe, life-threatening disease primarily affecting infants, with potential lifelong sequelae. Neisseria meningitidis (Nm) serogroup B (MenB) causes most IMD cases in Germany, many of which can be prevented with four-component MenB (4CMenB) vaccination. The potential public health and economic impact of introducing routine 4CMenB infant vaccination in Germany was assessed.

Methods

A dynamic transmission-based cost-effectiveness model adapted for Germany assessed the impact of infant 4CMenB universal mass vaccination (UMV) versus no vaccination. The model included the latest real-world evidence on vaccine effectiveness, the comprehensive burden of disease on patients (sequelae) and their family (quality of life impact), comprehensive German IMD costs, and vaccination uptake assumptions.

Results

The largest public health impact was predicted in children: a rapid decline, 5 years after UMV implementation, of 39.9% (34.7%) for MenB (all IMD) cases aged 0–4 years and 42.4% (36.8%) in infants. Over lifetime (100-year time horizon), 4CMenB could prevent 3154 MenB (3303 all IMD) cases, 291 MenB (304 all IMD) deaths and 1370 MenB (1435 all IMD) long-term sequelae. 4CMenB saved 25,878 quality-adjusted life-years (QALYs), at a cost of €188,762 per QALY gained in the base case (societal perspective including lost productivity). Scenarios including potential Nm carriage protection (enabling herd protection) or societal preferences for the prevention of severe diseases led to more cost-effective results, while a scenario excluding IMD impact beyond the patient with increased discounting of vaccination health benefits produced less cost-effective results.

Conclusions

MenB IMD is a vaccine-preventable disease. This analysis for Germany can inform decision-makers on the potential impact of introducing infant 4CMenB UMV. The program is predicted to rapidly produce health benefits (reduction in child cases, deaths and sequelae) at a cost per QALY to society of around €190,000 (base case), decreasing to around €78,000 when considering societal preferences and IMD underreporting.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40121-021-00573-w.

Invasive meningococcal disease (IMD) is an uncommon but severe infection, usually presenting as meningitis and/or sepsis, caused by the bacteria Neisseria meningitidis. Most cases occur in infants, young children and adolescents. Patients who survive the disease can develop lifelong sequelae, such as physical, neurological and psychological/behavioural problems that impact their quality of life and that of their family/caregivers. This disease can be prevented by vaccination. The use of the four-component meningococcal serogroup B vaccine (4CMenB) in countries like Germany can prevent the most common form of this disease, IMD caused by serogroup B. This study assessed the public health and economic impact of infant vaccination in Germany with 4CMenB. For this, the authors used an economic model that measured the lifetime impact of the disease on patients but also on their families. The model predicted that after 5 years of vaccination, the number of cases and deaths in infants and young children aged 0–4 years would rapidly decrease by almost 40%. Over a long-term horizon of 100 years, this number was predicted to remain stable. Due to the reduced number of cases, vaccination would also result in fewer deaths and patients with sequelae, as well as cost savings for the healthcare system and society due to the reduced loss of productivity. In conclusion, in Germany, IMD caused by serogroup B is preventable through vaccination, and the 4CMenB vaccine in German infants is predicted to rapidly reduce the disease burden, save lives and prevent healthcare costs.

Invasive serogroup B meningococci in England following three years of 4CMenB vaccination - First real-world data

OBJECTIVES

In 2015 the UK became the first country to implement the meningococcal B (MenB) vaccine, 4CMenB, into the national infant program. 4CMenB is expected to cover meningococci expressing sufficient levels of cross-reactive proteins. This study presents clonal complex, 4CMenB antigen genotyping, and 4CMenB coverage data for all English invasive MenB isolates from 2014/15 (1 year pre-vaccine) through 2017/18 and compares data from vaccinated and unvaccinated ≤3 year olds.

METHODS

Vaccine coverage of all invasive MenB isolates from 2014/15 to 2017/18 (n = 784) was analysed using the Meningococcal Antigen Typing System. Genotyping utilised the Meningococcus Genome Library.

RESULTS

Among ≤3 year olds, proportionally fewer cases in vaccinees (1, 2 or 3 doses) were associated with well-covered strains e.g. cc41/44 (20.5% versus 36.4%; P<0.01) and antigens e.g. PorA P1.4 (7.2% versus 17.3%; P = 0.02) or fHbp variant 1 peptides (44.6% vs 69.1%; P<0.01). Conversely, proportionally more cases in vaccinees were associated with poorly-covered strains e.g. cc213 (22.9% versus 9.6%; P<0.01) and antigens e.g. variant 2 or 3 fHbp peptides (54.2% versus 30.9%; P<0.01).

CONCLUSIONS

4CMenB reduces disease due to strains with cross-reactive antigen variants. No increase in absolute numbers of cases due to poorly covered strains was observed in the study period.

The Epidemiology of Invasive Meningococcal Disease in the Kingdom of Saudi Arabia: A Narrative Review with Updated Analysis

Reducing invasive meningococcal disease (IMD) through MenACWY immunization is a critical healthcare strategy in the Kingdom of Saudi Arabia (KSA). Robust IMD surveillance is essential to help assess the need for additional immunization initiatives in target populations. This is particularly important in KSA, where mass gatherings accompanying Hajj/Umrah pilgrimages have been associated with IMD outbreaks within the local KSA population, and subsequent intercontinental spread via returning pilgrims. This narrative review of the published literature describes the changing epidemiology of IMD in KSA to provide a perspective on the impact of current immunization strategies and potential gaps. As recent published surveillance data are lacking, we also evaluated publicly reported data from the KSA Ministry of Health (MoH) for 2012–2019 to inform more recent IMD trends. Between 1995 and 2011, national surveillance data indicate that 1103 IMD cases were reported in KSA: 60% in 2000–2001, involving two (mainly MenW) outbreaks involving KSA citizens/residents and pilgrims focused in Mecca and Medina. Across 2002–2011, 184 cases of IMD were reported, with a higher proportion occurring in KSA citizens/residents, and with less focus within pilgrimage centers than apparent in previous years. Our analysis of MoH data found that, between 2012 and 2019, 44 IMD cases were reported, all in KSA citizens/residents, and chiefly in children or infants. No pilgrimage-associated outbreaks have occurred since 2001. Serogroup data were available for 62.5% of all cases for 2002–2011; MenW (40.0%), MenA (35.7%), and MenB (16.5%). Serogroup data for 2012–2019 remain incompletely reported, and the existing surveillance system could be improved, as some element of underestimation/underreporting of IMD may exist. While existing MenACWY immunization strategies for KSA citizens/residents and visiting pilgrims have been successful in reducing IMD due to specific serogroups, disease due to MenB remains a potential risk, and additional immunization strategies should be considered.

Outcomes from the Use of Targeted Interventions to Increase Meningococcal Vaccination Rates in a Pediatric Clinic

Background

Meningococcal disease is a life-threatening illness that can cause sequelae such as neurological impairment, hearing loss, seizures, limb amputations, and scarring. Adolescents and young adults are at highest risk for contracting this disease which comes with a case-fatality ratio of 10–15%. Common serogroups in the United States are B, C, W, and Y, which are covered by two separate vaccines administered in a two-dose series. While MenACWY is routinely administered, the booster dose is often missed. Only 21.8% of teens reported receiving the MenB vaccine. While it is not currently part of routine care, recent outbreaks have been caused by serogroup B, prompting the need for increased vaccination rates.

Methods

MenACWY and MenB vaccination rates and demographic information were collected for 16–19-year-old patients in a pediatric clinic. Interventions including staff education, call logs, EMR communications to parents/guardians, and careful chart review were employed.

Results

At the time of baseline MenACWY data collection, there were N = 333 subjects between 16 and 19 years of age and N = 335 subjects between 16 and 19 years of age provided for MenB data. Upon completion, there were N = 319 subjects. Comparison of pre- and post-intervention data demonstrated a statistically significant increase in MenACWY series completion from 67.3 to 76.2% (p = 0.035) and a non-statistically significant increase in MenB completion from 6.9 to 10.3% (p = 0.197).

Conclusions

There was a statistically significant improvement in MenACWY but not MenB vaccination rates, indicating a need for more effective measures in addressing low MenB coverage.

Information needs during an emerging outbreak of meningococcal W135 disease in the Netherlands: a study among teenagers, their parents and healthcare professionals

BACKGROUND

To counter the rise in invasive meningococcal disease (IMD) serogroup W, the Netherlands introduced a menACWY catch-up vaccination campaign for teenagers in 2018 and 2019. Teenagers and parents who have questions or who seek advice from a professional about vaccinations are likely to consult a youth healthcare professional or their general practitioner. This study aimed to appraise the ability of these healthcare professionals to meet the information needs of teenagers and their parents at the start of the vaccination campaign.

METHODS

With online surveys, we assessed information needs in teenagers (N = 1603) and parents (N = 1784) concerning IMD and the menACWY vaccination, and in healthcare professionals (N = 520) in their communication with teenagers and parents. We additionally studied healthcare professionals' expectations of the information needs of teenagers and parents.

RESULTS

We identified several information needs about IMD and the menACWY vaccination in teenagers, parents and healthcare professionals. Some important commonalities in the information needs in these three groups were found, with regard to the topics IMD prevention, vaccine effectiveness and vaccine protection duration. Healthcare professionals' expectations of the information needs of teenagers and parents were quite accurate but some important discrepancies were found.

CONCLUSION

Our results suggest that healthcare professionals might not have been optimally equipped or prepared for questions from teenagers and their parents at the beginning of the vaccination campaign. We recommend public health institutes to timely assess and meet information needs about new vaccines in healthcare professionals to optimally equip them for consultations.

Lessons for and from the COVID-19 pandemic response - An appraisal of guidance for the public health management of Invasive Meningococcal Disease

BACKGROUND

COVID-19 has focussed public attention on the management of communicable disease like never before. Surveillance, contact tracing, and case management are recognised as key components of outbreak prevention. Development of guidance for COVID-19 has drawn from existing management of other communicable diseases, including Invasive Meningococcal Disease (IMD). IMD is a rare but severe outcome of Neisseria meningitidis infection that can be prevented through vaccination. Cases still occur sporadically, requiring ongoing surveillance and consistent management. To this end, national and international public health agencies have developed and published guidance for identification and management of IMD cases.

AIM

To assess national and international guidelines for the public health management of IMD, with a focus on the recommendations for identification and management of "close contacts" to IMD cases.

METHODS

Guidelines from six national and international public health agencies were assessed using a modified version of the Appraisal of Guidelines, Research and Evaluation (AGREE II) Instrument in four key domains: stakeholder involvement, developmental rigour, clarity, and applicability. A direct comparison of terminology and recommendations for identification and management of close contacts to IMD cases was also conducted.

RESULTS

Guidelines from Europe and the United Kingdom rated most highly using the AGREE II Instrument, both presenting a clear, critical assessment of the strength of the available evidence, and the risks, costs, and benefits behind recommendations for management of close contacts. Direct comparison of guidelines identified inconsistencies in the language defining close contacts to IMD cases.

CONCLUSION

Discrepancies between guidelines could be due to limited evidence concerning mechanisms behind disease transmission, along with the lack of a consistent process for development and review of guideline recommendations. COVID-19 management has demonstrated that international collaboration for development of public health guidance is possible, a practice that should be extended to management of other communicable diseases.

Household decision-making for the MenACWY vaccination: How parents and adolescents deal with an adolescent vaccination decision

OBJECTIVE

Between 2015 and 2018 The Netherlands experienced increases of invasive meningococcal disease (IMD) serogroup W (MenW), from 0.02 cases/100,000 people between 2010 and 2014 up to 0.5 cases/100,000 in 2017. Therefore in 2018 the MenACWY vaccination was introduced in the National Immunisation Programme (NIP) and a catch-up campaign was initiated among adolescents. This study aimed to gain insight into the decision-making process within households regarding the MenACWY vaccination. The focus was on the differences in the decision-making process of parents and adolescents and of those that had accepted the MenACWY vaccination and those that had not, in order to assess how these types of decisions are made within households.

METHOD

We conducted a total of 38 semi-structured interviews in 20 households (7 not vaccinated) with 20 parents and 18 adolescents (18 dyads) across The Netherlands concerning their decision-making process. Interview guides were constructed based on the Precaution Adaption Process (PAP) model. We performed thematic analysis using qualitative data analysis software (MAXQDA).

RESULTS

Parents are the main actors in the household decision-making process regarding the MenACWY vaccination. Parents start their decision-making process before adolescents are even aware of the issue. Households in the study took different approaches in involving the adolescent in the decision-making, resulting in three styles of household decision-making: parents decide without the adolescent, parents involve the adolescent, or parents leave it up to the adolescent to decide.

CONCLUSION

Parents influence adolescent reasoning, engagement and involvement during the MenACWY vaccination decision-making. And this is the case both among those that have accepted and rejected the MenACWY vaccination. Adolescent engagement with the MenACWY vaccination decision-making is either short-lived or non-existent. However, the moment offers opportunities to engage adolescents on vaccinations and decision-making, with parents as key figures to promote this.

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.

Oral and anal carriage of Neisseria meningitidis among sexually active HIV-infected men who have sex with men in Denmark 2014-15

INTRODUCTION

Outbreaks of invasive meningococcal disease (IMD) among men who have sex with men (MSM) caused by a hypervirulent, non-encapsulated Neisseria meningitidis (Nm) clone belonging to genogroup C have been described. We aimed to determine the oral and anal carriage rates and genogroups of Nm among MSM living with HIV.

METHODS

Sexually active MSM living with HIV were included. A questionnaire, an oral wash sample and an anal swab were collected at baseline and 12 months follow-up. Identification of Nm and genogrouping was performed using real-time polymerase chain reaction analysis.

RESULTS

Among 82 MSM, the Nm carriage rate was 31.7% (95% CI 21.9-42.9) at baseline. The oral carriage rate was 24.4% (95% CI 15.6-35.1) and the anal rate was 11.0% (95% CI 5.1-19.8). Non-groupable Nm were most prevalent followed by genogroup B and genogroup Y. Rates were similar at follow-up.

CONCLUSION

Strains of Nm were detected in both oral washes and anal samples in our study. Our results suggest that Nm may be transmitted sexually among MSM. Non-groupable Nm were predominant in our population and no genogroup C Nm were detected.

Use of Cost-Effectiveness Analyses for Decisions About Vaccination Programs for Meningococcal Disease in the United States, United Kingdom, The Netherlands, and Canada

INTRODUCTION

Meningococcal vaccines to protect against invasive meningococcal disease (IMD) vary in terms of vaccine technology and serogroup coverage (Polysaccharide MnACWY, conjugated C and ACWY, outer membrane vesicle-based or protein-based B vaccines), and the national recommendations for each of them vary in terms of target population and number of doses. We sought to understand factors associated with the evolution of meningococcal vaccination program recommendations in four countries with formal evaluation processes: the UK, US, the Netherlands, and Canada.

AREAS COVERED

A targeted review of published literature and internet sources for the four countries relating to meningococcal vaccination decision-making was conducted. The review focused on the impact of cost-effectiveness analyses on vaccine policy decisions and the extent to which variation in incidence of IMD and its potential catastrophic consequences influenced policy decisions.The evolution of meningococcal vaccine recommendations in the four countries was mainly driven by changes in vaccine availability and changes in serogroup incidence. Public pressure due to the catastrophic nature of IMD influenced recommendations. The role of cost-effectiveness analyses varied across the 4 countries.

EXPERT OPINION

The value of implementing meningococcal vaccination programs should be assessed using factors beyond those included in traditional cost-effectiveness analyses.

Meningococcal disease epidemiology in Brazil (2005-2018) and impact of MenC vaccination

BACKGROUND

Meningococcal disease (MD) presents a substantial public health problem in Brazil. Meningococcal C conjugate (MenC) vaccination was introduced into the routine infant immunization program in 2010, followed by adolescent vaccination in 2017. We evaluated changes in national and regional MD incidence and mortality between 2005 and 2018, serogroup distribution and vaccine coverage.

METHODS

Data were obtained from national surveillance systems from 2005 to 2018. Age-stratified incidence and mortality rates were calculated and a descriptive time-series analysis was performed comparing rates in the pre-(2005-2009) and post-vaccination (2011-2018) periods; MD due to specific meningococcal serogroups were analyzed in the pre-(2007-2009) and post-vaccination (2011-2018) periods.

RESULTS

From 2005 to 2018, 31,108 MD cases were reported with 6496 deaths; 35% of cases and deaths occurred in children < 5 years. Incidence and mortality rates declined steadily since 2012 in all age-strata, with significantly lower incidence and mortality in the post-vaccine introduction period in children aged < 1-year, 1-4 years, 5-9 years and 10-14 years. A significant decline in MenC disease in children < 5 years was observed following MenC vaccine introduction; infants < 1 year, from 3.30/100,000 (2007-2009) to 1.08/100,000 (2011-2018) and from 1.44/100,000 to 0.42/100,000 in 1-4-year-olds for these periods. Reductions in MenB disease was also observed. MenW remains an important cause of MD with 748 cases reported across 2005-2018. While initial infant vaccination coverage was high (>95% nationwide), this has since declined (to 83% in 2018); adolescent uptake was < 20% in 2017/18). Regional variations in outcomes and vaccine coverage were observed.

CONCLUSION

A substantial decline in incidence and mortality rates due to MD was seen following MenC vaccine introduction in Brazil, especially among children < 5 years chiefly driven by reductions in MenC serogroup. While these benefits are considerable, the prevalence of MD due to other serogroups such as MenW and MenB remains a concern. A video summary linked to this article can be found on Figshare: https://doi.org/10.6084/m9.figshare.13379612.v1.

Systematic literature review of the impact and effectiveness of monovalent meningococcal C conjugated vaccines when used in routine immunization programs

BACKGROUND

Monovalent meningococcal C conjugate vaccine (MCCV) was introduced into the routine immunization program in many countries in Europe and worldwide following the emergence of meningococcal serogroup C (MenC) in the late 1990s. This systematic literature review summarizes the immediate and long-term impact and effectiveness of the different MCCV vaccination schedules and strategies employed.

METHODS

We conducted a systematic literature search for peer-reviewed, scientific publications in the databases of MEDLINE (via PubMed), LILACS, and SCIELO. We included studies from countries where MCCV have been introduced in routine vaccination programs and studies providing the impact and effectiveness of MCCV published between 1st January 2001 and 31st October 2017.

RESULTS

Forty studies were included in the review; 30 studies reporting impact and 17 reporting effectiveness covering 9 countries (UK, Spain, Italy, Canada, Brazil, Australia, Belgium, Germany and the Netherlands). Following MCCV introduction, significant and immediate reduction of MenC incidence was consistently observed in vaccine eligible ages in all countries with high vaccine uptake. The reduction in non-vaccine eligible ages (especially population > 65 years) through herd protection was generally observed 3-4 years following introduction. Vaccine effectiveness (VE) was mostly assessed through screening methods and ranged from 38 to 100%. The VE was generally highest during the first year after vaccination and waned over time. The VE was better maintained in countries employing catch-up campaigns in older children and adolescents, compared to routine infant only schedules.

CONCLUSIONS

MCCV were highly effective, showing a substantial and sustained decrease in MenC invasive meningococcal disease. The epidemiology of meningococcal disease is in constant transition, and some vaccination programs now include adolescents and higher valent vaccines due to the recent increase in cases caused by serogroups not covered by MCCV. Continuous monitoring of meningococcal disease is essential to understand disease evolution in the setting of different vaccination programs.

Fifteen-minute consultation: Symptoms and signs of meningococcal disease

Meningococcal disease remains a leading cause of meningitis, sepsis and death in children worldwide and in the UK. Successful vaccination programmes in the UK have, however, significantly reduced the burden of disease in children. Unfortunately, despite vaccination, a significant number of children are still diagnosed with invasive meningococcal disease each year.As the prevalence of meningococcal disease falls, it is important that we maintain awareness of the symptoms and signs of meningococcal disease because the prompt recognition of this life-threatening infection improves outcomes.In this article we discuss the pathology, epidemiology and recognition of invasive meningococcal disease in children. The aim is to maintain awareness of this rare but life-threatening infection.

Meningococcal disease surveillance in the Asia-Pacific region (2020): The global meningococcal initiative

The degree of surveillance data and control strategies for invasive meningococcal disease (IMD) varies across the Asia-Pacific region. IMD cases are often reported throughout the region, but the disease is not notifiable in some countries, including Myanmar, Bangladesh and Malaysia. Although there remains a paucity of data from many countries, specific nations have introduced additional surveillance measures. The incidence of IMD is low and similar across the represented countries (<0.2 cases per 100,000 persons per year), with the predominant serogroups of Neisseria meningitidis being B, W and Y, although serogroups A and X are present in some areas. Resistance to ciprofloxacin is also of concern, with the close monitoring of antibiotic-resistant clonal complexes (e.g., cc4821) being a priority. Meningococcal vaccination is only included in a few National Immunization Programs, but is recommended for high-risk groups, including travellers (such as pilgrims) and people with complement deficiencies or human immunodeficiency virus (HIV). Both polysaccharide and conjugate vaccines form part of recommendations. However, cost and misconceptions remain limiting factors in vaccine uptake, despite conjugate vaccines preventing the acquisition of carriage.

A Comprehensive Review of Meningococcal Disease Burden in India

INTRODUCTION

Meningococcal disease caused by Neisseria meningitidis has a high case fatality rate. Of 12 distinct serogroups, A, B, C, W-135 (W) and Y cause the majority of infections. The meningococcal disease burden and epidemiology in India are not reliably known. Hence, we performed a narrative review with a systematically conducted search to summarize information on meningococcal disease burden and epidemiology and vaccination recommendations for meningococcal disease in India.

METHODS

A search of Medline and Embase databases was undertaken to identify relevant publications published in the last 25 years.

RESULTS

Results from 32 original publications, 11 of which were case reports, suggest a significant burden of meningococcal disease and related complications. Meningococcal disease is increasingly reported among adolescents and adults, and large outbreaks have been reported in this population. Meningococcal disease in India is caused almost exclusively by serogroup A; serogroups B, C, W and Y have also been documented. Meningococcal disease burden data remain unreliable because of limited disease surveillance, insufficient laboratory capacity, misdiagnosis and prevalence of extensive antibiotic use in India. Lack of access to healthcare also increases under-reporting, thus bringing the reliability of the data into question. Conjugate meningococcal vaccines are being used for disease prevention by national governments and immunization programs globally. In India, meningococcal vaccination is recommended only for certain high-risk groups, during outbreaks and for international travelers such as Hajj pilgrims and students pursuing studies abroad.

CONCLUSION

Meningococcal disease is prevalent in India but remains grossly underestimated and under-reported. Available literature largely presents outbreak data related to serogroup A disease; however, non-A serogroup disease cases have been reported. Reliable epidemiologic data are urgently needed to inform the true burden of endemic disease. Further research into the significance of meningococcal disease burden can be used to improve public health policy in India. Fig. 1 Plain language summary.

MenB-FHbp Vaccine Protects Against Diverse Meningococcal Strains in Adolescents and Young Adults: Post Hoc Analysis of Two Phase 3 Studies

Introduction

Two phase 3 studies in adolescents and young adults demonstrated that MenB-FHbp, a meningococcal serogroup B (MenB) vaccine, elicits protective immune responses after 2 or 3 doses based on serum bactericidal antibody assays using human complement (hSBA) against 4 primary and 10 additional diverse, vaccine-heterologous MenB test strains. Lower limits of quantitation (LLOQs; titers 1:8 or 1:16; titers ≥ 1:4 correlate with protection) were used to evaluate responses to individual strains and all 4 primary strains combined (composite response). A post hoc analysis evaluated percentages of subjects with protective responses to as many as 8 strains combined (4 primary plus additional strains).

Methods

Immune responses were measured using hSBAs against 4 primary strains in adolescents (n = 1509, MenB-FHbp; n = 898, hepatitis A virus vaccine/saline) and young adults (n = 2480, MenB-FHbp; n = 824, saline) receiving MenB-FHbp or control at 0, 2, and 6 months. Ten additional strains were evaluated in subsets of subjects from approximately 1800 MenB-FHbp recipients across both studies. Percentages of subjects with hSBA titers ≥ LLOQ for different numbers of primary strains or primary plus additional strains combined (7 or 8 strains total per subset) were determined before vaccination, 1 month post-dose 2, and 1 month post-dose 3.

Results

Across the panel of primary plus additional strains, at 1 month post-dose 3, titers ≥ LLOQ were elicited in 93.7–95.7% of adolescents and 91.7–95.0% of young adults for ≥ 5 test strains combined and in 70.5–85.8% of adolescents and 67.5–81.4% of young adults for ≥ 7 strains combined. Among adolescents, 99.8%, 99.0%, 92.8%, and 82.7% had titers ≥ LLOQ against at least 1, 2, 3, and all 4 primary strains, respectively; corresponding percentages for young adults were 99.7%, 97.7%, 94.0%, and 84.5%.

Conclusions

Results support the ability of MenB-FHbp to provide broad coverage against MenB strains expressing diverse FHbp variants.

Trial Registration

ClinicalTrials.gov identifiers NCT01830855, NCT01352845.

Electronic supplementary material

The online version of this article (10.1007/s40121-020-00319-0) contains supplementary material, which is available to authorized users.

Parental awareness and utilization of meningococcal serogroup B vaccines in the United States

Background

Meningococcal serogroup B (MenB) is the most common cause of invasive meningococcal disease (IMD) in the United States. The US Advisory Committee on Immunization Practices (ACIP) recommends vaccination of healthy adolescents against MenB based on shared clinical decision-making (Category B recommendation). This survey assessed factors associated with MenB vaccine awareness, utilization, and interest among parents/guardians of US adolescents.

Methods

Survey participants were identified in 2016 through KnowledgePanel®, an online random sample of US households; population-based weighting methodology was used to ensure data reflected a demographically representative population sample. Adults with ≥1 dependent aged 16–19 years were eligible and completed an online questionnaire. Respondents were grouped in terms of MenB vaccination of their child as: 1) vaccinated, 2) intending to vaccinate, 3) MenB vaccine-unaware, or 4) vaccine-aware but not intending to vaccinate. Univariate and multivariate analyses were used to identify factors influencing MenB vaccine awareness and utilization; univariate analyses used the weighted proportion of each group or weighted means, and multivariate analyses used logistic regression models based on the weighted study sample of each group.

Results

Six hundred nineteen parents/guardians participated, corresponding to 26,266,700 members of the US population after weighting. MenB vaccine awareness was significantly associated with parent race and sex. Specifically, 57% of parents were unaware of MenB vaccines, and there was significantly higher lack of awareness among males and those of Hispanic or non-White ethnicity. In addition, 36% of unaware parents/guardians were interested in and seeking MenB vaccine information from their healthcare provider (HCP), and there was higher interest among parents of Hispanic ethnicity. ‘Vaccinated/intending to vaccinate’ versus ‘not intending to vaccinate’ and ‘vaccinated’ versus ‘intending to vaccinate’ were both strongly associated with whether an HCP had recommended vaccination (odds ratios, 4.81 [95% CI 2.46, 9.35] and 5.66 [95% CI 2.46, 12.87], respectively).

Conclusions

Racial and socioeconomic disparities exist in the awareness and utilization of MenB vaccines among parents/guardians of US adolescents. HCP discussion and recommendation are critical catalysts for MenB vaccination and underscore the need to accurately interpret and implement the shared clinical decision-making (Category B) recommendation.

Transmissibility and pathogenicity of the emerging meningococcal serogroup W sequence type-11 complex South American strain: a mathematical modeling study

BACKGROUND

The recent emergence of strains belonging to the meningococcal serogroup W (MenW) sequence type-11 clonal complex and descending from the South American sub-lineage (MenW:cc11/SA) has caused significant shifts in the epidemiology of meningococcal disease worldwide. Although MenW:cc11/SA is deemed highly transmissible and invasive, its epidemiological characteristics have not yet been quantified.

METHODS

We designed a mathematical model of MenW transmission, carriage, and infection to analyze the recent epidemiology of invasive disease caused by MenW:cc11/SA strains and by other MenW strains in England and in France. We confronted that model with age-stratified incidence data to estimate the transmissibility and the invasiveness of MenW:cc11/SA in England, using the data in France as a validation cohort.

RESULTS

During the epidemiological years 2010/2011-2014/2015 in England, the transmissibility of MenW:cc11/SA relative to that of other MenW strains was estimated at 1.20 (95% confidence interval, 1.15 to 1.26). The relative invasiveness of MenW:cc11/SA was also found to exceed unity and to increase with age, with estimates ranging from 4.0 (1.6 to 9.7) in children aged 0-4 years to 20 (6 to 34) in adults aged ≥ 25 years. In France, the model calibrated in England correctly reproduced the early increase of MenW:cc11/SA disease during 2012/2013-2016/2017. Most recent surveillance data, however, indicated a decline in MenW:cc11/SA disease. In both countries, our results suggested that the transmission of MenW:cc11/SA carriage possibly started several months before the first reported case of MenW:cc11/SA disease.

DISCUSSION

Our results confirm earlier suggestions about the transmission and the pathogenic potential of MenW:cc11/SA. The main limitation of our study was the lack of age-specific MenW carriage data to confront our model predictions with. Furthermore, the lesser model fit to the most recent data in France suggests that the predictive accuracy of our model might be limited to 5-6 years.

CONCLUSIONS

Our study provides the first estimates of the transmissibility and of the invasiveness of MenW:cc11/SA. Such estimates may be useful to anticipate changes in the epidemiology of MenW and to adapt vaccination strategies. Our results also point to silent, prolonged transmission of MenW:cc11/SA carriage, with potentially important implications for epidemic preparedness.

School-based vaccination programmes: An evaluation of school immunisation delivery models in England in 2015/16

Schools are increasingly being used to deliver vaccines. In 2015/16 three school-based vaccination programmes were delivered to adolescents in England: human papillomavirus (HPV), meningococcal groups A, C, W and Y disease (MenACWY) and tetanus, diphtheria and polio (Td/IPV). We assessed how school delivery models impact vaccine coverage and how a delivery model for one programme may impact another. Routinely collected national data were analysed to ascertain the school grade achieving highest coverage within each one-dose programme and to compare two-dose delivery models (within year vs across years) for the HPV vaccine. We also assessed whether the HPV delivery model was associated with coverage in other programmes. MenACWY and Td/IPV coverage was highest in younger school grades. Overall similar HPV coverage was achieved with both models (86.7% two doses within one year, 85.8% two doses across two years, p = 0.20). High two-dose HPV coverage in 2015/16 was reported in areas that achieved high HPV coverage in 2013/14 when three doses were required. Areas with high three-dose coverage in 2013/14 achieved higher coverage with a within-one-year approach (92.0% vs 85.2%, p < 0.001), whilst areas reporting low coverage in 2013/14 achieved lower but similar coverage in 2015/16 with both models (79.2% vs 80.9% p = 0.29). MenACWY and Td/IPV coverage were higher in areas with high HPV coverage in 2013/14. Among high HPV coverage areas, MenACWY coverage was higher when HPV doses were delivered within year. School-based programmes should be offered as early as feasible and acceptable to optimise coverage. The choice of delivery model for HPV should take into account local performance and provider experience. Single providers may delivery multiple vaccines and the delivery for one programme may affect the performance of other programmes. Providers should consider local circumstances including past and current vaccine coverage and factors influencing coverage when deciding what delivery model to adopt.

Meningococcal carriage in young adults six years after meningococcal C conjugate (MCC) vaccine catch-up campaign in Salvador, Brazil

Meningococcal carriage studies are important to improve the knowledge of disease epidemiology as well as to support appropriate vaccination strategies. We conducted a cross-sectional study to determine the prevalence and genotypic characteristics of meningococci collected from young adults in Salvador, Brazil six years after a meningococcal C conjugate vaccine catch-up campaign. From August through November 2016, oropharyngeal swabs were collected from 407 students aged 1824 years attending a private college in Salvador, Brazil. Neisseria meningitidis was identified by standard microbiology methods and real time PCR. Genetic characteristics of meningococci were assessed by rt-PCR and/or whole genome sequencing. We also investigated potential factors associated with carriage. N. meningitidis was detectable in 50 students, 39 by both culture and rt-PCR, 7 by culture alone and 4 by rt-PCR alone, resulting in an overall meningococcal carriage prevalence of 12.3% (50/407). Carriage was independently associated with male sex (adjusted PR: 1.97; 95% CI: 1.12-3.46; p = 0.018) and attending bars or parties at least once per month (aPR: 3.31; 95% CI: 1.49-7.38; p = 0.003). Molecular tests identified 92% (46/50) N. meningitidis as non-groupable, of which 63% (29/46) had the capsule null genotype; 14 NG isolates contained disrupted capsule backbones and belonged to the following genogroups: 7 B, 3 Z, 3 E and 1 W. One isolate belonged to genogroup C tested only by PCR; 3 isolates contained a complete B capsule backbones, 2 of which were determined to be NG by slide agglutination serogrouping. While most meningococcal carriage isolates were non-groupable, there was a high degree of genetic diversity present in the collection, as evidenced by 25 unique STs being detected. The carriage prevalence of meningococcal serogroup C was low among young adults. Continuous vaccination is important to maintain reduced meningococcal carriage and transmission, inducing herd protection.

Emergence of new genetic lineage, ST-9316, of Neisseria meningitidis group W in Hauts-de-France region, France 2013-2018

BACKGROUND

The epidemiology of invasive meningococcal disease (IMD) is continuously changing in incidence, age distribution and/or the expansion of new strains of Neisseria meningitidis. The epidemiology of IMD due to group W (IMDW) has changed recently at a global level with the emergence of isolates belonging to the clonal complex ST-11 (CC11) derived from the South America-UK strain. A more recent change has been detected in France with the emergence of a new genotype distinct from CC11 that we aimed to analyse.

METHODS

Epidemiological and microbiological surveillance data in France were used in combination with whole genome sequencing (WGS) to detect emerging phenotypes and genotypes of IMD causing strains, and their susceptibility to immunity induced by the 4CMenB vaccine. Transgenic mice expressing the human transferrin were used to analyse the virulence of emerging strain isolates by direct comparison with CC11 isolates.

FINDINGS

Our data showed a local increase of IMDW isolates in north France since 2013. The isolates belonged to ST-9316 and few were ST-11 isolates. WGS clustered ST-9316 isolates together and were distantly separated from the isolates of the clonal complex ST-11 (CC11). Unlike cases due to W/CC11 isolates, cases due to W/ST-9316 isolates were mostly observed amongst infants under the age of 1 year but with lower mortality compared to W/CC11 cases. Genomic comparison showed that the W/ST-9316, unlike W/CC11 isolates, lacked the hmbR gene encoding the haemoglobin receptor that is a virulence factor involved in the acquisition of iron from haemoglobin. W/ST-9316 further showed lower virulence in mice compared to W/CC11 isolates.

INTERPRETATION

We report the emergence of a novel sequence type (ST-9316) mostly associated with serogroup W, and exhibiting a lower virulence and a distinct age specific incidence profile than W/CC11 isolates. Surveillance requires powerful approaches combining WGS and pathophysiological analysis to adapt control measures.

Cost-effectiveness of alternative strategies for vaccination of adolescents against serogroup B IMD with the MenB-FHbp vaccine in Canada

OBJECTIVE

Serogroup B meningococci (MnB) are now the largest cause of invasive meningococcal disease (IMD) in Canada. We assessed the clinical and economic impact of 3 adolescent MenB-FHbp immunization strategies.

METHODS

A population-based dynamic transmission model was developed to simulate the transmission of MnB among the entire Canadian population over a 30-year time horizon. Age group-based IMD incidence, bacterial carriage and transmission, disease outcomes, costs, and impact on quality of life were obtained from Canadian surveillance data and published literature. The vaccine was assumed to provide 85% protection against IMD and 26.6% against carriage acquisition. The model estimated the impact of routine vaccination with MenB-FHbp in 3 strategies: (1) age 14, along with existing school-based programs, with 75% uptake; (2) age 17 with 75% uptake, assuming school vaccination; and (3) age 17 with 30% uptake, assuming vaccination outside of school. Costs were calculated from the Canadian societal perspective.

RESULTS

With no vaccination, an estimated 3974 MnB cases would be expected over 30 years. Vaccination with strategies 1-3 were estimated to avert 688, 1033, and 575 cases, respectively. These outcomes were associated with incremental costs per quality-adjusted life-year of $976,000, $685,000, and $490,000.

CONCLUSIONS

Our model indicated that if the vaccine reduces risk of carriage acquisition, vaccination of older adolescents, even at lower uptake, could have a significant public health impact. Due to low disease incidence, MnB vaccination is unlikely to meet widely accepted cost-effectiveness thresholds, but evaluations of new programs should consider the overall benefits of the vaccination.

Invasive meningococcal disease: Timing and cause of death in England, 2008-2015

BACKGROUND

Neisseria meningitidis is a major cause of bacterial meningitis and septicaemia, with death often occurring rapidly after onset of the first symptoms. Later death can also occur, but may be due to other causes, such as underlying comorbidities. The study aimed to assess the timing and cause of death in patients with invasive meningococcal disease (IMD) prior to the introduction of two new meningococcal immunisation programmes in England.

METHODS

Public Health England (PHE) conducts IMD surveillance in England through its national meningococcal reference unit. Laboratory-confirmed IMD cases diagnosed during 2008-2015 were linked to weekly and annual electronic death registration records as well as the Patient Demographic Service (PDS) database.

RESULTS

Overall, 6734 of 6808 (99%) laboratory-confirmed IMD cases matched to PDS, including 668 fatalities. Of these, 667 linked to an annual death registration record compared to 405 reports linked to weekly death registrations. In total, 429/667 (64%) of all deaths and 428/502 (85%) of IMD-related deaths occurred within one day of diagnosis. In total, 498/667 (75%) deaths had occured by 30 days after IMD diagnosis and 98% (490/498) of these were IMD-related. Serogroup B contributed to 64% (323/502) of IMD-related deaths, followed by serogroup W (84/502, 17%) and serogroup Y (70/502, 14%). Deaths occurring after 30 days were less likely to be IMD-related, mainly amongst ≥65 year-olds, with malignancy, chronic respiratory and cardiac conditions predominating.

CONCLUSIONS

Most IMD-related deaths occurred within a day of diagnosis and nearly all IMD-related deaths occurred within 30 days of diagnosis. The rapidity of death highlights the importance of prevention through vaccination.

Variable clinical presentation by the main capsular groups causing invasive meningococcal disease in England

BACKGROUND

Invasive meningococcal disease (IMD) typically presents as meningitis, septicaemia or both. Atypical clinical presentations are rare but well-described. We aimed to assess the relationship between meningococcal capsular group, age, clinical presentation, diagnosis and outcome among IMD cases diagnosed in England during 2014.

METHODS

Public Health England conducts enhanced national surveillance of IMD in England. Clinical data for laboratory-confirmed MenB, MenW and MenY cases in ≥5 year-olds were used to classify presenting symptoms, diagnosis and outcomes. Multivariable logistic regression was used to assess independent associations between meningococcal capsular group, clinical presentation, gender, age and death.

RESULTS

In 2014, there were 340 laboratory-confirmed IMD cases caused by MenB (n = 179), MenW (n = 95) and MenY (n = 66). Clinical presentation with meningitis alone was more prevalent among MenB cases (28%) and among 15-24 year-olds (20%), whilst bacteraemic pneumonia was most prevalent among MenY cases (26%) and among ≥65 year-olds (24%). Gastrointestinal symptoms were recorded preceding or during presentation in 15% (40/269) cases with available information, including 5% (7/140) MenB, 17% (8/47) MenY and 30% (25/82) MenW cases. Upper respiratory tract symptoms were reported in 16% (22/141) MenB, 23% (11/47) MenY and 31% (26/84) MenW cases. Increasing age was also independently associated with bacteraemic meningococcal pneumonia, with no cases among 5-14 year-olds compared to 24% in ≥65 year-olds. Case fatality rates increased with age but no significant associations with death were identified.

CONCLUSIONS

Healthcare professionals should be aware of the atypical clinical presentations associated with the less prevalent meningococcal capsular groups in different age-groups.