Impact of a mass vaccination campaign against Serogroup B meningococcal disease in the Saguenay-Lac-Saint-Jean region of Quebec four years after its launch

4CMenB journey to the 10-year anniversary and beyond

The 4-component meningococcal serogroup B (MenB) vaccine, 4CMenB, the first broadly protective, protein-based MenB vaccine to be licensed, is now registered in more than 50 countries worldwide. Real-world evidence (RWE) from the last decade confirms its effectiveness and impact, with infant immunization programs showing vaccine effectiveness of 71-95% against invasive MenB disease and cross-protection against non-B serogroups, including a 69% decrease in serogroup W cases in 4CMenB-eligible cohorts in England. RWE from different countries also demonstrates the potential for additional moderate protection against gonorrhea in adolescents. The real-world safety profile of 4CMenB is consistent with prelicensure reports. Use of the endogenous complement human serum bactericidal antibody (enc-hSBA) assay against 110 MenB strains may enable assessment of the immunological effectiveness of multicomponent MenB vaccines in clinical trial settings. Equitable access to 4CMenB vaccination is required to better protect all age groups, including older adults, and vulnerable groups through comprehensive immunization policies.

4CMenB Vaccination to Prevent Meningococcal B Disease in Vietnam: Expert Review and Opinion

An advisory board meeting was held with experts in Vietnam (Hanoi, August 2022), to review the evidence on invasive meningococcal disease (IMD) epidemiology, clinical management, and meningococcal vaccines to reach a consensus on recommendations for meningococcal vaccination in Vietnam. IMD is a severe disease, with the highest burden in infants and children. IMD presents as meningitis and/or meningococcemia and can progress extremely rapidly. Almost 90% of deaths in children occur within the first 24 h, and disabling sequelae (e.g., limb amputations and neurological damage) occur in up to 20% of survivors. IMD patients are often hospitalized late, due to mild and nonspecific early symptoms and misdiagnosis. Difficulties related to diagnosis and antibiotic misuse mean that the number of reported IMD cases in Vietnam is likely to be underestimated. Serogroup B IMD is predominant in many regions of the world, including Vietnam, where 82% of IMD cases were due to serogroup B (surveillance data from 2012 to 2021). Four component meningococcal B vaccine (4CMenB) is used in many countries (and is part of the pediatric National Immunization Program in 13 countries), with infant vaccination starting from two months of age, and a 2 + 1 dosing schedule. Experts recommend 4CMenB vaccination as soon as possible in Vietnam, starting from two months of age, with a 2 + 1 dosing schedule, and at least completing one dose before 6 months of age.

Acceptance and socioeconomic inequalities in meningococcal B vaccination in the community of Madrid prior to its inclusion in the immunization schedule

INTRODUCTION

The main preventive measure against invasive meningococcal disease is vaccination. The aim of our study was to evaluate the acceptability of the meningococcal B (MenB) vaccine and socioeconomic inequalities in the access to the vaccine in the Community of Madrid in the period prior to its introduction in the immunization schedule.

MATERIALS AND METHODS

We conducted an observational and ecological descriptive study in the cohort of children born between 2016 and 2019 using population-based electronic records. We calculated the vaccination coverage and analysed factors associated with vaccination status, determined the spatial distribution of vaccination coverage and the deprivation index (DI) and assessed the association between them by means of spatial regression.

RESULTS

We observed an increasing trend in primary vaccination coverage, from 44% in the cohort born in 2016 to 68% in the 2019 cohort. We found a statistically significant association between vaccination status and the DI (OR of primary vaccination in areas with DI5 compared to areas with DP1, 0.38; 95% confidence interval, 0.39-0.50; P<.001). The spatial analysis showed an inverse correlation between the DI and vaccination coverage.

CONCLUSIONS

The rise in the coverages of the MenB vaccine shows acceptance by the population. The association between socioeconomic level and vaccination coverage confirms the existence of health inequality and underlines the importance including this vaccine in the immunization schedule.

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.

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

Importance

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

Objective

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

Design, Setting, and Participants

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

Exposures

Routine 4CMenB vaccination, per regional vaccination programs.

Main Outcomes and Measures

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

Results

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

Conclusions and Relevance

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

Challenges in synthesis of real-world vaccine effects on meningococcal serogroup B disease for 4CMenB vaccine post-licensure effectiveness studies: A systematic review

BACKGROUND

Real-world studies on vaccine effects are diverse in terms of objectives, study setting and design, data type and scope, and analysis methods. In this review, we describe and discuss four-component meningococcal serogroup B vaccine (4CMenB vaccine, Bexsero) real-world studies with the aim of synthesizing their findings with application of standard methods.

METHODS

We performed a systematic literature review of all real-world studies on 4CMenB vaccine effects on meningococcal serogroup B disease, with no restriction for population age, vaccination schedule and/or type of vaccine effect evaluated (vaccine effectiveness [VE] and vaccine impact [VI] outcomes) published since its licensure in 2013 (from January 2014 until July 2021) in PubMed, Cochrane and the grey literature. We then aimed to synthesize the findings of the identified studies through application of standard synthesis methods.

RESULTS

According to reported criteria we retrieved five studies presenting estimates on 4CMenB vaccine effectiveness and impact. These studies showed great diversity in population, vaccination schedule and analysis methods mainly due to diversity in vaccine strategies and recommendations in the study settings. Directed by this diversity, no quantitative pooling methods to synthesize findings could be applied; instead we descriptively assessed study methods. We report VE estimates ranging from 59% to 94% and VI estimates ranging from 31% to 75%, representing diverse age groups, vaccination schedules and analysis methods.

CONCLUSION

Both vaccine outcomes showed real-life effectiveness of 4CMenB vaccine despite differences in study methodologies and vaccination strategies. Based on appraisal of study methods, we highlighted the need for an adapted tool which facilitates synthesis of heterogenic real-world vaccine studies when quantitative pooling methods are not applicable.

Invasive Meningococcal Disease epidemiology and vaccination strategies in four Southern European countries: a review of the available data

INTRODUCTION

Invasive meningococcal disease (IMD) is a major health concern which can be prevented through vaccination. Conjugate vaccines against serogroups A, C, W and Y and two protein-based vaccines against serogroup B are currently available in the European Union.

AREAS COVERED

We present epidemiologic data for Italy, Portugal, Greece and Spain using publicly available reports from national reference laboratories and national or regional immunization programs (1999-2019), aiming to confirm risk groups, and describe time trends in overall incidence and serogroup distribution, as well as impact of immunization. Analysis of circulating MenB isolates in terms of the surface factor H binding protein (fHbp) using PubMLST is discussed as fHbp represents an important MenB vaccine antigen. Predictions of potential reactivity of the two available MenB vaccines (MenB-fHbp and 4CMenB) with circulating MenB isolates are also provided as assessed using the recently developed MenDeVAR tool.

EXPERT OPINION

Understanding dynamics of IMD and continued genomic surveillance are essential for evaluating vaccine effectiveness, but also prompting proactive immunization programs to prevent future outbreaks. Importantly, the successful design of further effective meningococcal vaccines to fight IMD relies on considering the unpredictable epidemiology of the disease and combining lessons learnt from capsule polysaccharide vaccines and protein-based vaccines.

4CMenB sustained vaccine effectiveness against invasive meningococcal B disease and gonorrhoea at three years post program implementation

OBJECTIVES

To evaluate persistence of vaccine effectiveness (VE) and vaccine impact (VI) on invasive meningococcal B (MenB) disease and gonorrhoea at three years after implementation of a state funded 4CMenB program for infants, children, adolescents and young people in South Australia.

METHODS

VI was assessed using a Poisson or negative binomial regression model, and VE was estimated using screening and case-control methods. Chlamydia controls were used to estimate VE in the primary analysis to control potential confounding effects such as high-risk sexual behaviour associated with sexually transmitted infections.

RESULTS

During the three-year program, reductions of 63.1% (95%CI 29.0% to 80.9%) and 78.5% (95%CI 33.0% to 93.1%) in incidence of MenB disease were observed in infants and adolescents, respectively. There were no cases in infants who had received three doses of 4CMenB. Two-dose VE against MenB disease was 90.7% (95%CI 6.9% to 99.1%) for the childhood program and 83.5% (95%CI 0 to 98.2%) for the adolescent program. Two-dose VE against gonorrhoea in adolescents was 33.2% (95%CI 15.9% to 47.0%). Lower VE estimates were demonstrated after 36 months post-vaccination (23.2% (95%CI 0 to 47.5%) >36 months post-vaccination compared to 34.9% (95%CI 15.0% to 50.1%) within 6-36 months). Higher VE estimates were found after excluding patients with repeat gonorrhoea infections (37.3%, 95%CI 19.8% to 51.0%). For gonorrhoea cases co-infected with chlamydia VE was maintained (44.7% (95%CI 17.1% to 63.1%).

CONCLUSION

The third-year evaluation results show persistent vaccine effectiveness of 4CMenB against MenB disease in infants and adolescents. As this is the first ongoing program for adolescents, moderate vaccine protection against gonorrhoea with waning effectiveness three years post-vaccination was demonstrated in adolescents and young adults. The additional protection of 4CMenB vaccine against gonorrhoea, likely through cross-protection should be considered in cost-effectiveness analyses. A booster dose may need to be further evaluated and considered in adolescents due to waning protection against gonorrhoea demonstrated after 36 months post-vaccination.

Primary Meningococcal Conjunctivitis in an Adult Patient

Primary meningococcal conjunctivitis from Neisseria meningitidis is a rare cause for acute, purulent conjunctivitis most commonly presenting in children. Here we present a case of primary meningococcal conjunctivitis in an adult patient with mild signs/symptoms mimicking non-gonococcal bacterial conjunctivitis. The patient was immediately treated with topical and systemic antibiotics. Here we highlight that an early diagnosis of a mild case can be missed thus, clinicians need to keep a high index of suspension as prompt recognition is important to initiate appropriate systemic antimicrobial therapy to prevent systemic disease.

Proceedings of the Expert Consensus Group meeting on meningococcal serogroup B disease burden and prevention in India

Meningococcal disease is highly transmissible, life-threatening and leaves significant sequelae in survivors. Every year, India, which has a plethora of risk factors for meningococcal disease, reports around 3000 endemic cases. However, the overall disease burden and serogroup distribution are unknown, creating a setting of general disease negligence and unawareness. Vaccination with quadrivalent meningococcal conjugate vaccine A, C, W, and Y is only recommended for high-risk children, and there is no overall guidance for meningococcal serogroup B (MenB) vaccination. MenB vaccines, which recently have been licensed in many countries but not in India, have significantly aided the fight against meningococcal disease. However, these MenB vaccines are not available in India. An Expert Consensus Group meeting was held with leading meningococcal disease experts to better understand the current disease epidemiology, particularly serogroup B, the prevalence gaps, and feasible ways to bridge them. The proceedings are presented in this paper.

Preventing invasive meningococcal disease in early infancy

This review considers the pathogenesis, diagnosis, and epidemiology of invasive meningococcal disease in infants, to examine and critique meningococcal disease prevention in this population through vaccination. High rates of meningococcal disease and poor outcomes, particularly for very young infants, highlight the importance of meningococcal vaccination in early infancy. Although effective and safe meningococcal vaccines are available for use from 6 weeks of age, they are not recommended globally. Emerging real-world data from the increased incorporation of these vaccines within immunization programs inform recommendations regarding effectiveness, appropriate vaccination schedule, possible long-term safety effects, and persistence of antibody responses. Importantly, to protect infants from IMD, national vaccination recommendations should be consistent with available data regarding vaccine safety, effectiveness, and disease risk.

[Infectious Disease Prevention Group: Update on vaccines, 2022]

The update of the preventive activities for this year 2022 in the field of infectious diseases is of special relevance due to the importance that prevention has gained and more specifically, vaccination as a tool to control the pandemic caused by the SARS-CoV-2 virus declared on March 11, 2020. The pandemic has focused much of the prevention efforts on its containment, but the importance of maintaining high vaccination coverage of the rest of the recommended vaccines to maintain good control of vaccine-preventable diseases and avoid complications in particularly vulnerable patients should not be forgotten. In this year's review we present a practical document with the aim of providing tools to primary care professionals who work with adults, to make the indication of each vaccine whether it is systematically recommended or if it is because the patient belongs to some risk group due to their condition or underlying pathology. In this way, throughout the document, we will comment on the most innovative aspects of systematic vaccination (flu, pneumococcus, meningococcal vaccines and vaccines against the human papillomavirus [HPV]), the new vaccines (pandemic vaccines against COVID-19, vaccines against herpes zoster of subunits, vaccines against monkeypox) and the recommended vaccines according to risk condition (pregnancy and lactation, travelers, patients with immunosuppression or underlying pathology).

Public health perspective of a pentavalent meningococcal vaccine combining antigens of MenACWY-CRM and 4CMenB

OBJECTIVES

Invasive meningococcal disease (IMD) is a life-threatening disease that can rapidly progress to death or leave survivors with severe, life-long sequelae. Five meningococcal serogroups (A, B, C, W and Y) account for nearly all IMD. Meningococcal serogroup distribution fluctuates over time across the world and age groups. Here, we consider the potential public health impact of a pentavalent MenABCWY vaccine developed to help further control meningococcal disease and improve immunisation rates.

RESULTS

The GSK MenABCWY vaccine combines the antigenic components of MenACWY-CRM (Menveo®) and 4CMenB (Bexsero®), building on a wide body of clinical experience and real-world evidence. Both approved vaccines have acceptable safety profiles, demonstrate immunogenicity, and are broadly used, including in national immunisation programmes in several countries. Since the advent of quadrivalent vaccines, public health in relation to IMD has improved, with a decline in the overall incidence of IMD and an increase in vaccine coverage.

CONCLUSION

A pentavalent MenABCWY has the potential to provide further public health benefits through practical, broad IMD protection programmes encompassing serogroups A, B, C, W and Y, and is currently in late-stage development.

Serogroup B meningococcal disease in persons previously vaccinated with a serogroup B meningococcal vaccine - United States, 2014-2019

Since serogroup B meningococcal (MenB) vaccines became available in the United States, six serogroup B meningococcal disease cases have been reported in MenB-4C (n = 4) or MenB-FHbp (n = 2) recipients. Cases were identified and characterized through surveillance and health record review. All five available isolates were characterized using whole genome sequencing; four isolates (from MenB-4C recipients) were further characterized using flow cytometry, MenB-4C-induced serum bactericidal activity (SBA), and genetic Meningococcal Antigen Typing System (gMATS). Three patients were at increased meningococcal disease risk because of an outbreak or underlying medical conditions, and only four of the six patients had completed a full 2-dose MenB series. Isolates were available from 5 patients, and all contained sub-family A FHbp. The four isolates from MenB-4C recipients expressed NhbA but were mismatched for the other MenB-4C vaccine antigens. These four isolates were relatively resistant to MenB-4C-induced SBA, but predicted by gMATS to be covered. Overall, patient risk factors, incomplete vaccine series completion, waning immunity, and strain resistance to SBA likely contributed to disease in these six patients.

Evaluation of a prototype decontamination mobile unit (UMDEO) for COVID-19 vaccination: A cross-sectional survey in France

AIM OF THE STUDY

In the context of the worldwide vaccination campaign against COVID-19, France has been deploying multiple sites for mass vaccination. This study aimed to assess the perceived usefulness of a prototype decontamination mobile unit (UMDEO) for COVID-19 vaccination among both the patient and healthcare providers perspectives.

METHODS

This was a descriptive cross-sectional study conducted in Toulouse over two days. UMDEO is a fully comprehensive, versatile solution that was deployed as a 5-row vaccination unit. A written questionnaire was distributed from March 6th-7th, 2021 among all patients presenting for vaccination at the mobile center, as well as the team participating in the vaccination campaign.

RESULTS

Among the vaccinated patients (n = 1659), 1409 participants (84.9%) filled out the survey, as well as 68 out of 85 (80%) within the UMDEO team. The maximum patient rate was 98 people per hour. The majority of participants and caregivers (1307 [93.2%] and 67 [98.5%] respectively) agreed that the mobile unit increased access to vaccination. A total of 91.3% patients (n = 1281) and 95.6% caregivers (n = 65) believed that it would speed up the overall vaccination campaign.

CONCLUSION

The majority of the vaccinated population and of the team participating in the survey were satisfied with the usefulness of UMDEO as a vaccination center. Toulouse is currently the only city to have used such a structure for vaccination, but it could be used as a basis for planning other mobile units to increase vaccination access.

Meningococcal Disease Outbreaks: A Moving Target and a Case for Routine Preventative Vaccination

Outbreaks of invasive meningococcal disease (IMD) are unpredictable, can be sudden and have devastating consequences. We conducted a non-systematic review of the literature in PubMed (1997-2020) to assess outbreak response strategies and the impact of vaccine interventions. Since 1997, IMD outbreaks due to serogroups A, B, C, W, Y and X have occurred globally. Reactive emergency mass vaccination campaigns have encompassed single institutions (schools, universities) through to whole sections of the population at regional/national levels (e.g. serogroup B outbreaks in Saguenay-Lac-Saint-Jean region, Canada and New Zealand). Emergency vaccination responses to IMD outbreaks consistently incurred substantial costs (expenditure on vaccine supplies, personnel costs and interruption of other programmes). Impediments included the limited pace of transmission of information to parents/communities/healthcare workers; issues around collection of informed consents; poor vaccine uptake by older adolescents/young adults, often a target age group; issues of reimbursement, particularly in the USA; and difficulties in swift supply of large quantities of vaccines. For serogroup B outbreaks, the need for two doses was a significant issue that contributed substantially to costs, delayed onset of protection and non-compliance with dose 2. Real-world descriptions of outbreak control strategies and the associated challenges systematically show that reactive outbreak management is administratively, logistically and financially costly, and that its impact can be difficult to measure. In view of the unpredictability, fast pace and potential lethality of outbreak-associated IMD, prevention through routine vaccination appears the most effective mitigation tool. Highly effective vaccines covering five of six disease-causing serogroups are available. Preparedness through routine vaccination programmes will enhance the speed and effectiveness of outbreak responses, should they be needed (ready access to vaccines and need for a single booster dose rather than a primary series).

4CMenB vaccine and its role in preventing transmission and inducing herd immunity

INTRODUCTION

: Vaccination is the most effective method of protecting people from invasive meningococcal disease (IMD). Of all the capsular groups, B is the most common cause of invasive meningococcal disease in many parts of the world. Despite this, adolescent meningococcal B vaccine programs have not been implemented globally, partly due to the lack of evidence for herd immunity afforded by meningococcal B vaccines.

AREAS COVERED

This review aims to synthesise the available evidence on recombinant 4CMenB vaccines' ability to reduce pharyngeal carriage and therefore provide indirect (herd) immunity against IMD.

EXPERT OPINION

There is some evidence that the 4CMenB vaccine may induce cross-protection against non-B carriage of meningococci. However, the overall body of evidence does not support a clinically significant reduction in carriage of disease-associated or group B meningococci following 4CMenB vaccination. No additional cost-benefit from herd immunity effects should be included when modelling the cost-effectiveness of 4CMenB vaccine programs against group B IMD. 4CMenB immunisation programs should focus on direct (individual) protection for groups at greatest risk of meningococcal disease.

Future meningococcal B and combination vaccines being developed should consider the impact of the vaccine on carriage as part of their clinical evaluation.

Meningococcal disease and vaccination in college students

Neisseria meningitidis is a bacterial pathogen capable of causing rapidly progressing illness from nonspecific symptoms to end-organ failure or death in a matter of hours to days. Despite the availability of meningococcal vaccines, there remains a notable disease incidence peak among individuals aged 18-19 years, with college students at increased risk for disease relative to non-college students. Between 2007 and 2017, as many as one in five colleges in the United States experienced an outbreak of meningococcal disease at their own or a nearby institution. Evidence-based strategies to promote meningococcal vaccination among students can be adapted for the college setting, but barriers exist that limit widespread implementation of these strategies by colleges. In this article, we review meningococcal disease characteristics and epidemiology among US college students, vaccination indications and coverage levels among US college students, as well as college vaccination policies and practices that can impact students' vaccine uptake.

Effectiveness of Meningococcal Vaccines at Reducing Invasive Meningococcal Disease and Pharyngeal Neisseria meningitidis Carriage: A Systematic Review and Meta-analysis

BACKGROUND

Invasive meningococcal disease (IMD), caused by Neisseria meningitidis, leads to significant morbidity and mortality worldwide. This review aimed to establish the effectiveness of meningococcal vaccines at preventing IMD and N. meningitidis pharyngeal carriage.

METHODS

A search within PubMed, Embase, Scopus, and unpublished studies up to 1 February 2020 was conducted.

RESULTS

After removal of duplicates, 8565 studies were screened and 27 studies included. Protection was provided by meningococcal C vaccines for group C IMD (odds ratio [OR], 0.13 [95% confidence interval {CI}, .07-.23]), outer membrane vesicle (OMV) vaccines against group B IMD (OR, 0.35 [95% CI, .25-.48]), and meningococcal A, C, W, Y (MenACWY) vaccines against group ACWY IMD (OR, 0.31 [95% CI, .20-.49]). A single time series analysis found a reduction following an infant 4CMenB program (incidence rate ratio, 0.25 [95% CI, .19-.36]). Multivalent MenACWY vaccines did not reduce carriage (relative risk [RR], 0.88 [95% CI, .66-1.18]), unlike monovalent C vaccines (RR, 0.50 [95% CI, .26-.97]). 4CMenB vaccine had no effect on group B carriage (RR, 1.12 [95% CI, .90-1.40]). There was also no reduction in group B carriage following MenB-FHbp vaccination (RR, 0.98 [95% CI, .53-1.79]).

CONCLUSIONS

Meningococcal conjugate C, ACWY, and OMV vaccines are effective at reducing IMD. A small number of studies demonstrate that monovalent C conjugate vaccines reduce pharyngeal N. meningitidis carriage. There is no evidence of carriage reduction for multivalent MenACWY, OMV, or recombinant MenB vaccines, which has implications for immunization strategies.

CLINICAL TRIALS REGISTRATION

CRD42018082085 (PROSPERO).

Exploring the Ability of Meningococcal Vaccines to Elicit Mucosal Immunity: Insights from Humans and Mice

Neisseria meningitidis causes a devastating invasive disease but is also a normal colonizer of the human nasopharynx. Due to the rapid progression of disease, the best tool to protect individuals against meningococcal infections is immunization. Clinical experience with polysaccharide conjugate vaccines has revealed that an ideal meningococcal vaccine must prevent both invasive disease and nasal colonization, which confers herd immunity. However, not all meningococcal vaccines are equal in their ability to prevent nasal colonization, for unknown reasons. Herein, we describe recent efforts to utilize humanized mouse models to understand the impact of different meningococcal vaccines on nasal colonization. These mice are susceptible to nasal colonization, and they become immune following live nasal infection or immunization with matched capsule-conjugate or protein-based vaccines, replicating findings from human work. We bring together insights regarding meningococcal colonization and immunity from clinical work with findings using humanized mouse models, providing new perspective into the different determinants of mucosal versus systemic immunity. Then, we use this as a framework to help focus future studies toward understanding key mechanistic aspects left unresolved, including the bacterial factors required for colonization and immune evasion, determinants of nasal mucosal protection, and characteristics of an ideal meningococcal vaccine.

Translating meningococcal serogroup B vaccines for healthcare professionals

INTRODUCTION

Vaccination is an effective strategy to combat invasive meningococcal disease (IMD). Vaccines against the major disease-causing meningococcal serogroups are available; however, development of vaccines against serogroup B faced particular challenges, including the inability to target traditional meningococcal antigens (i.e. polysaccharide capsule) and limited alternative antigens due to serogroup B strain diversity. Two different recombinant, protein-based, serogroup B (MenB) vaccines that may address these challenges are currently available. These vaccines have been extensively evaluated in pre-licensure safety and immunogenicity trials, and recently in real-world studies on effectiveness, safety, and impact on disease burden.

AREAS COVERED

This review provides healthcare professionals, particularly pediatricians, an overview of currently available MenB vaccines, including development strategies and evaluation of coverage.

EXPERT OPINION

Overall, recombinant MenB vaccines are valuable tools for healthcare professionals to protect patients against IMD. Their development required innovative design approaches that overcame challenging hurdles and identified novel protein antigen targets; however, important distinctions in the approaches used in their development, evaluation, and administration exist and many unanswered questions remain. Healthcare providers frequently prescribing MenB vaccines are challenged to keep abreast of these differences to ensure patient protection against this serious disease.

Recent advances in meningococcal B disease prevention: real-world evidence from 4CMenB vaccination

OBJECTIVES

4CMenB is a broadly protective vaccine against invasive meningococcal capsular group B disease (MenB IMD). Licensed worldwide based on immunogenicity and safety data, effectiveness and impact data are now available. We comprehensively reviewed all available real-world evidence gathered from use of 4CMenB since licensure.

RESULTS

Data from 7 countries provide evidence of effectiveness and impact across different healthcare settings and age-groups, including national/regional immunization programs, observational studies and outbreak control. At least 2 4CMenB doses reduced MenB IMD by 50%-100% in 2-month to 20-year-olds depending on length of follow-up. Estimates of vaccine effectiveness in fully vaccinated cohorts ranged from 59%-100%. The safety profile of 4CMenB administered in real-world settings was consistent with pre-licensure clinical trial data.

CONCLUSION

MenB IMD is an uncommon but life-threatening disease with unpredictable epidemiology. The substantial body of data demonstrating 4CMenB effectiveness and impact supports its use in IMD prevention. The results reinforce the importance of direct protection of the highest risk groups; infants/young children and adolescents. Direct protection via routine infant immunization with catch-up in young children and routine adolescent vaccination could be the preferred option for MenB disease control. A Video Abstract linked to this article is available on Figshare: https://doi.org/10.6084/m9.figshare.14546790.

TIPICO X: report of the 10th interactive infectious disease workshop on infectious diseases and vaccines

TIPICO is an expert meeting and workshop that aims to provide the most recent evidence in the field of infectious diseases and vaccination. The 10th Interactive Infectious Disease TIPICO workshop took place in Santiago de Compostela, Spain, on November 21-22, 2019. Cutting-edge advances in vaccination against respiratory syncytial virus, Streptococcus pneumoniae, rotavirus, human papillomavirus, Neisseria meningitidis, influenza virus, and Salmonella Typhi were discussed. Furthermore, heterologous vaccine effects were updated, including the use of Bacillus Calmette-Guérin (BCG) vaccine as potential treatment for type 1 diabetes. Finally, the workshop also included presentations and discussion on emergent virus and zoonoses, vaccine resilience, building and sustaining confidence in vaccination, approaches to vaccine decision-making, pros and cons of compulsory vaccination, the latest advances in decoding infectious diseases by RNA gene signatures, and the application of big data approaches.

Endogenous complement human serum bactericidal assay (enc-hSBA) for vaccine effectiveness assessments against meningococcal serogroup B

Immunogenicity of vaccines against meningococcal serogroup B (MenB) has been assessed pre-licensure with a human serum bactericidal activity assay (hSBA), tested against small numbers of strains. We report the qualification/validation of an alternative qualitative hSBA which uses endogenous complement (enc-hSBA) present in the vaccinee’s serum. Serum samples were collected from adults pre-vaccination and post-vaccination with the 4-component MenB vaccine (4CMenB). A representative panel of invasive isolates and 4 antigen-specific indicator strains were used in qualification experiments. Each strain was tested in ≥3 experiments with pre/post-vaccination sera to evaluate intermediate precision. A 110-strain panel and the 4 indicator strains met qualification criteria, demonstrating assay precision. Assay robustness, specificity and sensitivity were demonstrated using the 4 indicator strains. Enc-hSBA is highly standardized, allows testing across large panels of epidemiologically-relevant MenB strains, and accounts for complement activity differences between vaccinees. Therefore, enc-hSBA enables a more accurate estimation of effectiveness for vaccines against MenB.

Impact of Meningococcal B Vaccine on Invasive Meningococcal Disease in Adolescents

Background

From 2017, a statewide cluster randomized trial was conducted in South Australia to assess the impact of the meningococcal B vaccine 4CMenB on pharyngeal Neisseria meningitidis carriage in adolescents. Senior schools were randomized to receive the vaccine in 2017 (intervention) or 2018 (control). In this study we report the vaccine impact of 4CMenB on serogroup B invasive meningococcal disease (IMD) in 16- to 19-year-old adolescents in South Australia.

Methods

This observational time series analysis of serogroup B IMD cases compares the 14 years prior to the commencement of the trial (2003–2016) with the 2 years following 4CMenB vaccination of the 2017 adolescent cohort.

Results

Approximately 62% of year 10 and 11 students (15–16 years old) in South Australia enrolled in the trial. A total of 30 522 year 10–12 students received at least 1 dose of 4CMenB. The number of serogroup B IMD cases in 16- to 19-year old adolescents in South Australia increased on average by 10% per year from 2003 to 2016 (95% confidence interval [CI], 6%–15%, P &lt; .001), peaking with 10 cases in 2015. Serogroup B IMD cases reduced to 5 in 2017–2018 and 1 in 2018–2019, below the expected numbers of 9.9 (95% prediction interval [PI], 3.9–17.5) and 10.9 (95% PI, 4.4–19.1), respectively. This translated to an overall reduction in the number of serogroup B IMD cases of 71% (95% CI, 15%–90%, P = .02). There were no serogroup B IMD cases in vaccinated adolescents.

Conclusions

Vaccinating adolescents with 4CMenB was associated with a reduction in group B meningococcal disease in South Australia.

Clinical Trials Registration

NCT03089086.

Genomic surveillance of Neisseria meningitidis serogroup B invasive strains: Diversity of vaccine antigen types, Brazil, 2016-2018

Background

Neisseria meningitidis serogroup B remains a prominent cause of invasive meningococcal disease (IMD) in Brazil. Because two novel protein-based vaccines against serogroup B are available, the main purpose of this study was to provide data on the diversity and distribution of meningococcal vaccine antigen types circulating in Brazil.

Methodology

Genetic lineages, vaccine antigen types, and allele types of antimicrobial-associated resistance genes based on whole-genome sequencing of a collection of 145 Neisseria meningitidis serogroup B invasive strains recovered in Brazil from 2016 to 2018 were collected.

Results

A total of 11 clonal complexes (ccs) were identified among the 145 isolates, four of which were predominant, namely, cc461, cc35, cc32, and cc213, accounting for 72.0% of isolates. The most prevalent fHbp peptides were 24 (subfamily A/variant 2), 47 (subfamily A/variant 3), 1 (subfamily B/variant 1) and 45 (subfamily A/variant 3), which were predominantly associated with cc35, cc461, cc32, and cc213, respectively. The NadA peptide was detected in only 26.2% of the isolates. The most frequent NadA peptide 1 was found almost exclusively in cc32. We found seven NHBA peptides that accounted for 74.5% of isolates, and the newly described peptide 1390 was the most prevalent peptide exclusively associated with cc461. Mutated penA alleles were detected in 56.5% of the isolates, whereas no rpoB and gyrA mutant alleles were found.

Conclusion

During the study period, changes in the clonal structure of circulating strains were observed, without a predominance of a single hyperinvasive lineage, indicating that an epidemiologic shift has occurred that led to a diversity of vaccine antigen types in recent years in Brazil.

Vaccines against Meningococcal Diseases

Neisseria meningitidis is the main cause of meningitis and sepsis, potentially life-threatening conditions. Thanks to advancements in vaccine development, vaccines are now available for five out of six meningococcal disease-causing serogroups (A, B, C, W, and Y). Vaccination programs with monovalent meningococcal serogroup C (MenC) conjugate vaccines in Europe have successfully decreased MenC disease and carriage. The use of a monovalent MenA conjugate vaccine in the African meningitis belt has led to a near elimination of MenA disease. Due to the emergence of non-vaccine serogroups, recommendations have gradually shifted, in many countries, from monovalent conjugate vaccines to quadrivalent MenACWY conjugate vaccines to provide broader protection. Recent real-world effectiveness of broad-coverage, protein-based MenB vaccines has been reassuring. Vaccines are also used to control meningococcal outbreaks. Despite major improvements, meningococcal disease remains a global public health concern. Further research into changing epidemiology is needed. Ongoing efforts are being made to develop next-generation, pentavalent vaccines including a MenACWYX conjugate vaccine and a MenACWY conjugate vaccine combined with MenB, which are expected to contribute to the global control of meningitis.

Meningococcal Vaccination: Recommendations of the Advisory Committee on Immunization Practices, United States, 2020

This report compiles and summarizes all recommendations from CDC's Advisory Committee on Immunization Practices (ACIP) for use of meningococcal vaccines in the United States. As a comprehensive summary and update of previously published recommendations, it replaces all previously published reports and policy notes. This report also contains new recommendations for administration of booster doses of serogroup B meningococcal (MenB) vaccine for persons at increased risk for serogroup B meningococcal disease. These guidelines will be updated as needed on the basis of availability of new data or licensure of new meningococcal vaccines. ACIP recommends routine vaccination with a quadrivalent meningococcal conjugate vaccine (MenACWY) for adolescents aged 11 or 12 years, with a booster dose at age 16 years. ACIP also recommends routine vaccination with MenACWY for persons aged ≥2 months at increased risk for meningococcal disease caused by serogroups A, C, W, or Y, including persons who have persistent complement component deficiencies; persons receiving a complement inhibitor (e.g., eculizumab [Soliris] or ravulizumab [Ultomiris]); persons who have anatomic or functional asplenia; persons with human immunodeficiency virus infection; microbiologists routinely exposed to isolates of Neisseria meningitidis; persons identified to be at increased risk because of a meningococcal disease outbreak caused by serogroups A, C, W, or Y; persons who travel to or live in areas in which meningococcal disease is hyperendemic or epidemic; unvaccinated or incompletely vaccinated first-year college students living in residence halls; and military recruits. ACIP recommends MenACWY booster doses for previously vaccinated persons who become or remain at increased risk.In addition, ACIP recommends routine use of MenB vaccine series among persons aged ≥10 years who are at increased risk for serogroup B meningococcal disease, including persons who have persistent complement component deficiencies; persons receiving a complement inhibitor; persons who have anatomic or functional asplenia; microbiologists who are routinely exposed to isolates of N. meningitidis; and persons identified to be at increased risk because of a meningococcal disease outbreak caused by serogroup B. ACIP recommends MenB booster doses for previously vaccinated persons who become or remain at increased risk. In addition, ACIP recommends a MenB series for adolescents and young adults aged 16-23 years on the basis of shared clinical decision-making to provide short-term protection against disease caused by most strains of serogroup B N. meningitidis.

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

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

Success of 4CMenB in preventing meningococcal disease: evidence from real-world experience

Meningococcal disease remains one of the most feared infectious diseases worldwide because of its sudden onset, rapid progression and high case fatality rates, while survivors are often left with severe long-term sequelae. Young children have the highest incidence of invasive meningococcal disease (IMD), and nearly all cases in the UK, as in most of Europe and many other industrialised countries, are due to group B meningococci (MenB). The licensure of a broad-coverage, recombinant protein-based MenB vaccine (4CMenB) in 2013 was, therefore, heralded a major breakthrough in the fight against IMD. This vaccine was, however, licensed on immunogenicity and reactogenicity studies only, raising uncertainties about field effectiveness, long-term safety and antibody persistence. In 2015, the UK became the first country to implement 4CMenB into the national infant immunisation schedule and, since then, several countries have followed suit. Seven years after licensure, a wealth of real-world data has emerged to confirm 4CMenB effectiveness, along with large-scale safety data, duration of protection in different age groups, successful strategies to reduce vaccine reactogenicity, impact on carriage in adolescents and the potential for 4CMenB to protect against other meningococcal serogroups and against gonorrhoea. A number of questions, however, remain unanswered, including the investigation and management of vaccine-associated fever in infants, as well as disease severity and assessment of breakthrough cases in immunised children. Increasing use of 4CMenB will provide answers in due course. We now have vaccines against all the major serogroups causing IMD worldwide. Next-generation and combination vaccines against multiple serogroups look very promising.

Methods to evaluate serogroup B meningococcal vaccines: From predictions to real-world evidence

Serogroup B meningococci (MenB) remain a prominent cause of invasive meningococcal disease (IMD). The protein-based multicomponent 4CMenB and the bivalent MenB-FHbp are the only currently available vaccines against MenB-caused IMD. Efficacy studies are not possible, due to the low incidence of IMD. Therefore, the vaccines' immunogenicity has been evaluated against several target strains chosen to quantify complement-mediated killing induced by each vaccine component in the serum bactericidal antibody assay. However, due to the wide genetic diversity and different expression levels of vaccine antigens across MenB strains, vaccine performance may differ from one strain to another. Here, we review the methods used to predict MenB strain coverage for 4CMenB and MenB-FHbp. Phenotypic assays such as the meningococcal antigen typing system (MATS, 4CMenB-specific) and the flow cytometric meningococcal antigen surface expression assay (MEASURE; MenB-FHbp-specific) were developed. Genomic approaches are also available, such as genetic MATS (gMATS) and the Bexsero antigen sequence type (BAST) scheme, both 4CMenB-specific. All methods allow tentative predictions of coverage across MenB strains, including that afforded by each vaccine antigen, and are rapid and reproducible. Real-world data on vaccine effectiveness are needed to confirm predictions obtained by these methods.

The everchanging epidemiology of meningococcal disease worldwide and the potential for prevention through vaccination

Neisseria meningitidis is a major cause of bacterial meningitis and septicaemia worldwide and is associated with high case fatality rates and serious life-long complications among survivors. Twelve serogroups are recognised, of which six (A, B, C, W, X and Y) are responsible for nearly all cases of invasive meningococcal disease (IMD). The incidence of IMD and responsible serogroups vary widely both geographically and over time. For the first time, effective vaccines against all these serogroups are available or nearing licensure. Over the past two decades, IMD incidence has been declining across most parts of the world through a combination of successful meningococcal immunisation programmes and secular trends. The introduction of meningococcal C conjugate vaccines in the early 2000s was associated with rapid declines in meningococcal C disease, whilst implementation of a meningococcal A conjugate vaccine across the African meningitis belt led to near-elimination of meningococcal A disease. Consequently, other serogroups have become more important causes of IMD. In particular, the emergence of a hypervirulent meningococcal group W clone has led many countries to shift from monovalent meningococcal C to quadrivalent ACWY conjugate vaccines in their national immunisation programmes. Additionally, the recent licensure of two protein-based, broad-spectrum meningococcal B vaccines finally provides protection against the most common group responsible for childhood IMD across Europe and Australia. This review describes global IMD epidemiology across each continent and trends over time, the serogroups responsible for IMD, the impact of meningococcal immunisation programmes and future needs to eliminate this devastating disease.

Culture-Confirmed Invasive Meningococcal Disease in Canada, 2010 to 2014: Characterization of Serogroup B Neisseria meningitidis Strains and Their Predicted Coverage by the 4CMenB Vaccine

Laboratory surveillance of invasive meningococcal disease (IMD) is important to our understanding of the evolving nature of the Neisseria meningitidis strain types causing the disease and the potential coverage of disease strains by the newly developed vaccines. This study examined the molecular epidemiology of culture-confirmed IMD cases in Canada by examining the strain types and the potential coverage of a newly licensed 4CMenB vaccine on Canadian serogroup B N. meningitidis strains. The strain types identified in different parts of Canada appeared to be unique as well as their predicted coverage by the 4CMenB vaccine. These data were compared to data obtained from previous studies done in Canada and elsewhere globally. For effective control of IMD, laboratory surveillance of this type was found to be essential and useful to understand the dynamic nature of this disease.

The molecular epidemiology of culture-confirmed invasive meningococcal disease (IMD) in Canada from 2010 to 2014 was studied with an emphasis on serogroup B Neisseria meningitidis (MenB) isolates, including their predicted coverage by the 4CMenB vaccine. The mean annual incidence rates of culture confirmed IMD varied from 0.19/100,000 in Ontario to 0.50/100,000 in New Brunswick and 0.59/100,000 in Quebec. In both Quebec and Atlantic region, MenB was significantly more common than other serogroups, while in other provinces, both MenB and serogroup Y (MenY) were almost equally common. The majority of MenB cases (67.0%) were in those aged ≤24 years, while most MenC (75.0%) and MenY (69.6%) cases were in adults more than 24 years old. The 349 MenB isolates were grouped into 103 sequence types (STs), 90 of which belonged to 13 clonal complexes (CCs). A large number of 4CMenB antigen genes were found among the Canadian MenB, which is predicted to encode 50 factor H binding protein (fHbp) types, 40 NHBA types, and 55 PorA genotypes. Provinces and regions were found to have their own unique MenB STs. A meningococcal antigen typing system assay predicted an overall MenB coverage by 4CMenB to be 73.6%, with higher coverage predicted for the two most common STs: 100% for ST154 and 95.9% for ST269, leading to higher coverage in both the Atlantic region and Quebec. Higher coverage (81.4%) was also found for MenB recovered from persons aged 15 to 24 years, followed by strains from infants and children ≤4 years old (75.2%) and those aged 5 to 14 years (75.0%).

IMPORTANCE Laboratory surveillance of invasive meningococcal disease (IMD) is important to our understanding of the evolving nature of the Neisseria meningitidis strain types causing the disease and the potential coverage of disease strains by the newly developed vaccines. This study examined the molecular epidemiology of culture-confirmed IMD cases in Canada by examining the strain types and the potential coverage of a newly licensed 4CMenB vaccine on Canadian serogroup B N. meningitidis strains. The strain types identified in different parts of Canada appeared to be unique as well as their predicted coverage by the 4CMenB vaccine. These data were compared to data obtained from previous studies done in Canada and elsewhere globally. For effective control of IMD, laboratory surveillance of this type was found to be essential and useful to understand the dynamic nature of this disease.

Epidemiology and Control of Meningococcal Disease in Canada: A Long, Complex, and Unfinished Story

The epidemiology of meningococcal disease in Canada has been punctuated by outbreaks caused by serogroup A strains in the 1940s, virulent serogroup C clones from 1985 to 2001, a serogroup B clone in Quebec from 2003 to 2014, and more recently a W clone in British Columbia. Region- and province-wide immunization campaigns have been implemented to control these outbreaks using meningococcal C polysaccharide and conjugate vaccines, a quadrivalent ACWY conjugate vaccine, and a serogroup B protein-based vaccine. Meningococcal C conjugate vaccines have been included in routine immunization programs for children, and ACWY conjugate vaccines have been included in school-based programs for adolescents in most jurisdictions. In contrast, serogroup B protein-based vaccines were only recommended and used for high-risk individuals and to control outbreaks. Currently, the immunization schedules adopted in provinces and territories are not uniform. This is not explained by notable epidemiologic differences. Publicly funded immunization programs are the result of a complex decision-making process. Political factors including public opinion, media attention, interest groups' advocacy campaigns, decision-makers' priorities and budgetary constraints have played important roles in shaping meningococcal programs in Canada, and this should be recognized. As the recent occurrence of outbreaks caused by virulent W clones shows, continued investments in epidemiological surveillance at both the provincial and national levels are necessary, so there can be early warning and informed decisions can be made.