Meningococcal Carriage Following a Vaccination Campaign With MenB-4C and MenB-FHbp in Response to a University Serogroup B Meningococcal Disease Outbreak-Oregon, 2015-2016

Effectiveness of quadrivalent meningococcal conjugate vaccine against meningococcal carriage and genotype character changes: A secondary analysis of prospective cohort study in Korean military trainees

OBJECTIVE

We evaluated the changes and molecular epidemiology of meningococcal carriage in military recruits after quadrivalent meningococcal conjugate vaccines (MenACWY) vaccination.

METHODS

Oropharyngeal swabs were obtained at the beginning and end of the 5-week training. Carriage rates before and after vaccination were compared to estimate vaccine effectiveness (VE). Cultured isolates were characterized by multi-locus sequence typing (MLST).

RESULTS

Of 866 vaccinated participants, the overall carriage rate was 10.6% prior to MenACWY vaccination and it tended to decrease to 9.5% after 5 weeks of vaccination (P =0.424). Carriage rate of serogroup ACWY decreased significantly after vaccination (VEACWY = 72.6%, 95%CI: 36.3 - 88.2%), and serogroup C was particularly reduced (VEC = 83.0%, 95%CI: 50.6 - 94.1%), whereas nongroupable isolates increased significantly after vaccination (VENG = -76.1%, 95%CI: -176.2 - -13.1%). Among 99 carriage isolates with complete MLST profiles, 45 different sequence types with nine clonal complexes (CCs) were identified, and 35.3% of the carriage isolates belonged to hypervirulent strains such as CC-32, CC-41/44, and CC-269.

CONCLUSIONS

MenACWY vaccination in military recruits led to reduced carriage rates of serogroups C, W, and Y within a short 5-week period. However, serogroup B isolates belonging to the hypervirulent lineage remained after the implementation of MenACWY vaccination.

Meningococcal Vaccination of Adolescents in the United States: Past Successes and Future Considerations

Invasive meningococcal disease (IMD) is a rare but serious illness, and adolescents and young adults in the United States are at increased risk. Here, we discuss US IMD history and how successful disease prevention through routine vaccination against the most common disease-causing serogroups (A, B, C, W, and Y) can inform future recommendations. Before the introduction of quadrivalent meningococcal conjugate (MenACWY) vaccines, most US cases of IMD were caused by serogroups B, C, and Y. After recommendation by the Advisory Committee on Immunization Practices for routine MenACWY vaccination of 11-12-year-olds in 2005, followed by a 2010 booster recommendation, MenCWY disease incidence declined dramatically, and vaccine coverage remains high. Two serogroup B (MenB) vaccines are licensed in the United States, but uptake is low compared with MenACWY vaccines, likely because Advisory Committee on Immunization Practices recommends MenB vaccination subject to shared clinical decision-making rather than routinely for all adolescents. The proportion of adolescent IMD caused by MenB has now increased. Pentavalent vaccines that protect against serogroups A, B, C, W, and Y may provide an optimal strategy for improving vaccination rates to ultimately reduce MenB incidence while maintaining the historically low rates of IMD caused by serogroups A, C, W, and Y.

Multicentre double-blind randomised placebo-controlled trial evaluating the efficacy of the meningococcal B vaccine, 4CMenB (Bexsero), against Neisseria gonorrhoeae infection in men who have sex with men: the GoGoVax study protocol

INTRODUCTION

Gonorrhoea, the sexually transmissible infection caused by Neisseria gonorrhoeae, has a substantial impact on sexual and reproductive health globally with an estimated 82 million new infections each year worldwide. N. gonorrhoeae antimicrobial resistance continues to escalate, and disease control is largely reliant on effective therapy as there is no proven effective gonococcal vaccine available. However, there is increasing evidence from observational cohort studies that the serogroup B meningococcal vaccine four-component meningitis B vaccine (4CMenB) (Bexsero), licensed to prevent invasive disease caused by Neisseria meningitidis, may provide cross-protection against the closely related bacterium N. gonorrhoeae. This study will evaluate the efficacy of 4CMenB against N. gonorrhoeae infection in men (cis and trans), transwomen and non-binary people who have sex with men (hereafter referred to as GBM+).

METHODS AND ANALYSIS

This is a double-blind, randomised placebo-controlled trial in GBM+, either HIV-negative on pre-exposure prophylaxis against HIV or living with HIV (CD4 count >350 cells/mm3), who have had a diagnosis of gonorrhoea or infectious syphilis in the last 18 months (a key characteristic associated with a high risk of N. gonorrhoeae infection). Participants are randomised 1:1 to receive two doses of 4CMenB or placebo 3 months apart. Participants have 3-monthly visits over 24 months, which include testing for N. gonorrhoeae and other sexually transmissible infections, collection of demographics, sexual behaviour risks and antibiotic use, and collection of research samples for analysis of N. gonorrhoeae-specific systemic and mucosal immune responses. The primary outcome is the incidence of the first episode of N. gonorrhoeae infection, as determined by nucleic acid amplification tests, post month 4. Additional outcomes consider the incidence of symptomatic or asymptomatic N. gonorrhoeae infection at different anatomical sites (ie, urogenital, anorectum or oropharynx), incidence by N. gonorrhoeae genotype and antimicrobial resistance phenotype, and level and functional activity of N. gonorrhoeae-specific antibodies.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the St Vincent's Hospital Human Research Ethics Committee, St Vincent's Hospital Sydney, NSW, Australia (ref: 2020/ETH01084). Results will be disseminated in peer-reviewed journals and via presentation at national and international conferences.

TRIAL REGISTRATION NUMBER

NCT04415424.

The important lessons lurking in the history of meningococcal epidemiology

INTRODUCTION

The epidemiology of invasive meningococcal disease (IMD), a rare but potentially fatal illness, is typically described as unpredictable and subject to sporadic outbreaks.

AREAS COVERED

Meningococcal epidemiology and vaccine use during the last ~ 200 years are examined within the context of meningococcal characterization and classification to guide future IMD prevention efforts.

EXPERT OPINION

Historical and contemporary data highlight the dynamic nature of meningococcal epidemiology, with continued emergence of hyperinvasive clones and affected regions. Recent shifts include global increases in serogroup W disease, meningococcal antimicrobial resistance (AMR), and meningococcal urethritis; additionally, unvaccinated populations have experienced disease resurgences following lifting of COVID-19 restrictions. Despite these changes, a close analysis of meningococcal epidemiology indicates consistent dominance of serogroups A, B, C, W, and Y and elevated IMD rates among infants and young children, adolescents/young adults, and older adults. Demonstrably effective vaccines against all 5 major disease-causing serogroups are available, and their prophylactic use represents a powerful weapon against IMD, including AMR. The World Health Organization's goal of defeating meningitis by the year 2030 demands broad protection against IMD, which in turn indicates an urgent need to expand meningococcal vaccination programs across major disease-causing serogroups and age-related risk groups.

Serum bactericidal activity against circulating and reference strains of meningococcal serogroup B in the United States: A review of the strain coverage of meningococcal serogroup B (MenB) vaccines in adolescents and young adults

Invasive meningococcal disease (IMD) is rare but associated with high morbidity and mortality. In the United States, the most vulnerable age groups are infants and adolescents/young adults, and the most common type of IMD is caused by serogroup B (MenB). MenB is preventable among adolescents and young adults with the use of two licensed vaccines, MenB-FHbp (Trumenba®, bivalent rLP2086; Pfizer Inc, Collegeville, PA) and MenB-4C (Bexsero®; GSK Vaccines, Srl, Italy). Because the effectiveness of MenB vaccination is dependent on broad vaccine coverage across circulating disease-causing strains, we reviewed the available clinical and real-world evidence regarding breadth of coverage of the two licensed vaccines in adolescents and young adults in the United States. Both vaccines protect against various MenB strains. More controlled data regarding breadth of coverage across MenB strains are available for MenB-FHbp compared with MenB-4C, whereas more observational data regarding US outbreak strain susceptibility are available for MenB-4C.

Epidemiology of Meningococcal Disease in Four South American Countries and Rationale of Vaccination in Adolescents from the Region: Position Paper of the Latin American Society of Pediatric Infectious Diseases (SLIPE)

Surveillance of meningococcal disease (MD) is crucial after the implementation of vaccination strategies to monitor their impact on disease burden. Adolescent vaccination could provide direct and indirect protection. Argentina, Brazil, and Chile have introduced meningococcal conjugate vaccines (MCV) into their National Immunization Programs (NIP), while Uruguay has not. Here, we analyze the epidemiology of MD and vaccination experience from these four South American countries to identify needs and plans to improve the current vaccination programs.

METHODOLOGY

Descriptive study of MD incidence rates, serogroup distribution, case fatality rates (CFR), and MCV uptakes during the period 2010-2021 in Argentina, Brazil, Chile, and Uruguay. Data were extracted from national surveillance programs, reference laboratories, NIPs, and Pubmed.

RESULTS

MD overall incidence from 2010 to 2021 have a decreasing trend in Argentina (0.37 [IQR = 0.20-0.61]), Brazil (0.59 [IQR = 0.54-1.22]), and Chile (0.45 [IQR = 0.40-0.77]), while a significant increase in Uruguay (0.47 [IQR = 0.33-0.69]) was found from 2016 to 2019. During the COVID-19 pandemic, all countries sharply reduced their MD incidence. The highest incidence rates were observed among infants, followed by children 1-4 years of age. No second peak was evident in adolescents. A reduction in serogroup C, W, and Y cases has occurred in Argentina, Brazil, and Chile after introduction of MCV, serogroup B becoming predominant in all four countries. Median CFR was 9.0%, 21%, 19.9%, and 17.9% in Argentina, Brazil, Chile, and Uruguay, respectively. Median uptake of MCV for Argentina and Brazil were 66.6% and 91.0% for priming in infants; 54.7% and 84.5% for booster in toddlers; and 47.5% and 53% for adolescents; while for Chile, 95.6% for toddlers.

CONCLUSIONS

Experience after the implementation of MCV programs in South America was successful, reducing the burden of MD due to the vaccine serogroups. High vaccine uptake and the inclusion of adolescents will be crucial in the post-pandemic period to maintain the protection of the population. The increase in the proportion of serogroup B cases emphasizes the importance of continuous surveillance to guide future vaccination strategies.

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.

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.

Neisseria meningitidis carriage rate, antibiotic susceptibility profile, and associated factors among prisoners at Jimma zonal correction facility in Jimma Town, Southwestern Ethiopia: a cross-sectional study

Background

Neisseria meningitidis causes severe life-threatening meningococcal disease with a case fatality rate of 10–15% even with proper treatment. In Ethiopia, particularly in our study area, inadequate information is found on meningococcal disease. So, this study aimed to assess N. meningitidis carriage rate, antibiotic susceptibility profile, and associated factors among prisoners in Jimma Town, Southwestern Ethiopia.

Methods

A cross-sectional study was conducted in Jimma town, Southwest Ethiopia, from May to October 2019. A stratified sampling technique was used and proportional allocation was done. A total of 550 oropharyngeal swabs were collected, processed, isolated, and identified N. meningitidis using standard microbiological techniques. Antibiotics susceptibility test was done for isolates using the disk diffusion method. Data on demographic and associated factors for carriage were collected using a structured questionnaire. Data were summarized using frequency, percentage, graph, and table. A logistic regression model was used to see the association between the dependent and independent variables. Variables with a p-value < 0.25 during bivariate analysis were included in multivariate analysis to identify factors significantly associated with the meningococcal carriage and, a p-value < 0.05 was considered statistically significant.

Result

Out of the 550 study participants, 76(13.8%) with (CI: 7.20–18.20) were found carriers of N meningitidis. The predominant isolates were non-serogroupable 26(34.2%) and serogroup W/Y 22(28.9%), respectively. N. meningitidis isolates showed highest sensitivity to chloramphenicol 74(97.4%). Meningococcal carriage rate was significantly associated with being age group of 16–20 years; having respiratory symptoms within 3 months and active cigarette smoking within 3 months.

Conclusions

The majority of participants harbor most of the serogroups responsible for invasive cases of meningococcal disease. Respiratory symptoms, active cigarette smoking, and age group of 16–20 years increased the risk of N. meningitidis pharyngeal carriage rate. This study suggests providing better health education to control respiratory symptoms, smoking, and providing antibiotic prophylaxis for prisoners.

Predictors of meningococcal vaccine uptake in university and college students: a systematic review and meta-analysis

Objective: To identify predictors of meningococcal vaccine uptake among university and college students, the most common carriers of meningococcal disease. Participants: University or college students aged 18 to 25 years. Methods: Multiple databases, citations, and gray literature were systematically searched in April 2017 and January 2019, for articles reporting rates and predictors of vaccine uptake. Included studies underwent quality appraisal, and, where suitable, meta-analyses were performed. Results: Twenty-one articles, covering 18 studies from six countries, were included. They were mostly cross-sectional surveys of routine vaccination. Meta-analyses were conducted on six predictors. Higher vaccination uptake was associated with being a first year student, an undergraduate student, not being an international student, perceiving meningococcal disease as a risk, and being female. Conclusion: Identified key predictors correspond with previous studies and other vaccines. The findings should inform the delivery and communication of meningococcal vaccination to university and college students.

Impact of meningococcal ACWY conjugate vaccines on pharyngeal carriage in adolescents: evidence for herd protection from the UK MenACWY programme

OBJECTIVES

Serogroup W and Y invasive meningococcal disease (IMD) increased globally from 2000 onwards. Responding to a rapid increase in serogroup W clonal complex 11 (W:cc11) IMD, the UK replaced an adolescent booster dose of meningococcal C conjugate vaccine with quadrivalent MenACWY conjugate vaccine in 2015. By 2018, vaccine coverage in the eligible school cohorts aged 14-19 years-old was 84%. We assessed the impact of the MenACWY vaccination programme on meningococcal carriage.

METHODS

An observational study of culture-defined oropharyngeal meningococcal carriage prevalence before and after the start of the MenACWY vaccination programme in UK school students, aged 15-19 years, using two cross-sectional studies: 2014-15 "UKMenCar4" and 2018 "Be on the TEAM" (ISRCTN75858406).

RESULTS

A total of 10625 participants pre-implementation and 13434 post-implementation were included. Carriage of genogroups C, W, and Y (combined) decreased from 2·03% to 0·71% (OR 0·34 [95% CI 0·27-0·44] p<0·001). Carriage of genogroup B meningococci did not change (1·26% vs 1·23% [95% CI 0.77-1.22] p=0·80) and genogroup C remained rare (n = 7/10625 vs 17/13488, p=0·135). The proportion of serogroup positive isolates, i.e., those expressing capsule, decreased for genogroup W by 53.8% (95% CI -5.0%-79.8%, p=0·016) and for genogroup Y by 30·1% (95% CI 8·9%-46·3%, p=0·0025).

CONCLUSIONS

The UK MenACWY vaccination programme reduced carriage acquisition of genogroup and serogroup Y and W meningococci and sustained low levels of genogroup C carriage. These data support the use of quadrivalent MenACWY conjugate vaccine for indirect (herd) protection.

Correlates of protection for meningococcal surface protein vaccines; current approaches for the determination of breadth of coverage

INTRODUCTION

The two currently licensed surface protein non capsular meningococcal serogroup B (MenB) vaccines both have the purpose of providing broad coverage against diverse MenB strains. However, the different antigen compositions and approaches used to assess breadth of coverage currently make direct comparisons complex.

AREAS COVERED

In the second of two companion papers, we comprehensively review the serology and factors influencing breadth of coverage assessments for two currently licensed MenB vaccines.

EXPERT OPINION

Surface protein MenB vaccines were developed using different approaches, resulting in unique formulations and thus their breadth of coverage. The surface proteins used as vaccine antigens can vary among meningococcal strains due to gene presence/absence, sequence diversity and differences in protein expression. Assessment of the breadth of coverage provided by vaccines is influenced by the ability to induce cross-reactive functional immune responses to sequence diverse protein variants; the characteristics of the circulating invasive strains from specific geographic locations; methodological differences in the immunogenicity assays; differences in human immune responses between individuals; and the maintenance of protective antibody levels over time. Understanding the proportion of meningococcal strains which are covered by the two licensed vaccines is important in understanding protection from disease and public health use.

Meningococcal Disease in Pediatric Age: A Focus on Epidemiology and Prevention

Meningococcal disease is caused by Neisseria meningitidis; 13 serogroups have been identified and differentiated from each other through their capsular polysaccharide. Serotypes A, B, C, W, X, and Y are responsible for nearly all infections worldwide. The most common clinical manifestations are meningitis and invasive meningococcal disease, both characterized by high mortality and long-term sequelae. The infection rate is higher in children younger than 1 year and in adolescents, who are frequently asymptomatic carriers. Vaccination is the most effective method of preventing infection and transmission. Currently, both monovalent meningococcal vaccines (against A, B, and C serotypes) and quadrivalent meningococcal vaccines (against serogroups ACYW) are available and recommended according to local epidemiology. The purpose of this article is to describe the meningococcal vaccines and to identify instruments that are useful for reducing transmission and implementing the vaccination coverage. This aim could be reached by switching from the monovalent to the quadrivalent vaccine in the first year of life, increasing vaccine promotion against ACYW serotypes among adolescents, and extending the free offer of the anti-meningococcal B vaccine to teens, co-administering it with others proposed in the same age group. Greater awareness of the severity of the disease and increased health education through web and social networks could represent the best strategies for promoting adhesion and active participation in the vaccination campaign. Finally, the development of a licensed universal meningococcal vaccine should be another important objective.

Outbreak of invasive meningococcal disease caused by a meningococcus serogroup B in a nursery school, Wallonia, Belgium, 2018

Although most invasive meningococcal disease (IMD) cases are sporadic without identified transmission links, outbreaks can occur. We report three cases caused by meningococcus B (MenB) at a Belgian nursery school over 9 months. The first two cases of IMD occurred in spring and summer 2018 in healthy children (aged 3–5 years) attending the same classroom. Chemoprophylaxis was given to close contacts of both cases following regional guidelines. The third case, a healthy child of similar age in the same class as a sibling of one case, developed disease in late 2018. Microbiological analyses revealed MenB with identical finetype clonal complex 269 for Case 1 and 3 (unavailable for Case 2). Antimicrobial susceptibility testing revealed no antibiotic resistance. Following Case 3, after multidisciplinary discussion, chemoprophylaxis and 4CMenB (Bexsero) vaccination were offered to close contacts. In the 12-month follow-up of Case 3, no additional cases were reported by the school. IMD outbreaks are difficult to manage and generate public anxiety, particularly in the case of an ongoing cluster, despite contact tracing and management. This outbreak resulted in the addition of MenB vaccination to close contacts in Wallonian regional guidelines, highlighting the potential need and added value of vaccination in outbreak management.

Genomic Insights on Variation Underlying Capsule Expression in Meningococcal Carriage Isolates From University Students, United States, 2015-2016

In January and February 2015, Neisseria meningitidis serogroup B (NmB) outbreaks occurred at two universities in the United States, and mass vaccination campaigns using MenB vaccines were initiated as part of a public health response. Meningococcal carriage evaluations were conducted concurrently with vaccination campaigns at these two universities and at a third university, where no NmB outbreak occurred. Meningococcal isolates (N = 1,514) obtained from these evaluations were characterized for capsule biosynthesis by whole-genome sequencing (WGS). Functional capsule polysaccharide synthesis (cps) loci belonging to one of seven capsule genogroups (B, C, E, W, X, Y, and Z) were identified in 122 isolates (8.1%). Approximately half [732 (48.4%)] of isolates could not be genogrouped because of the lack of any serogroup-specific genes. The remaining 660 isolates (43.5%) contained serogroup-specific genes for genogroup B, C, E, W, X, Y, or Z, but had mutations in the cps loci. Identified mutations included frameshift or point mutations resulting in premature stop codons, missing or fragmented genes, or disruptions due to insertion elements. Despite these mutations, 49/660 isolates expressed capsule as observed with slide agglutination, whereas 45/122 isolates with functional cps loci did not express capsule. Neither the variable capsule expression nor the genetic variation in the cps locus was limited to a certain clonal complex, except for capsule null isolates (predominantly clonal complex 198). Most of the meningococcal carriage isolates collected from student populations at three US universities were non-groupable as a result of either being capsule null or containing mutations within the capsule locus. Several mutations inhibiting expression of the genes involved with the synthesis and transport of the capsule may be reversible, allowing the bacteria to switch between an encapsulated and non-encapsulated state. These findings are particularly important as carriage is an important component of the transmission cycle of the pathogen, and understanding the impact of genetic variations on the synthesis of capsule, a meningococcal vaccine target and an important virulence factor, may ultimately inform strategies for control and prevention of disease caused by this pathogen.

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.

'B Part of It' School Leaver study: a repeat cross-sectional study to assess the impact of increasing coverage with meningococcal B (4CMenB) vaccine on carriage of Neisseria meningitidis

BACKGROUND

Recombinant protein-based vaccines targeting serogroup B meningococci protect against invasive disease, but impacts on carriage are uncertain. This study assessed carriage prevalence of disease-associated meningococci from 2018-2020, as the proportion of vaccinated adolescents increased following introduction of a school-based 4CMenB immunisation program.

METHODS

Eligible participants who completed high school (age 17-25) in South Australia in the previous year had an oropharyngeal swab taken and completed a risk factor questionnaire. Disease-associated meningococci (genogroups A, B, C, W, X, Y) were detected by meningococcal and genogroup-specific polymerase chain reaction.

RESULTS

The final analysis included 4104 participants in 2018, 2690 in 2019, and 1338 in 2020. The proportion vaccinated with 4CMenB increased from 43% in 2018, to 78% in 2019, and 76% in 2020. Carriage prevalence of disease-associated meningococci in 2018 was 225/4104 (5.5%). There was little difference between the carriage prevalence in 2019 (134/2690, 5.0%, adjusted odds ratio [aOR] 0.82, 95% CI 0.64-1.05) and 2020 (68/1338, 5.1% aOR 0.82, 95% CI 0.57-1.17) compared to 2018.

CONCLUSIONS

Increased 4CMenB uptake in adolescents was not associated with a decline in carriage of disease-associated meningococci. 4CMenB immunisation programs should focus on direct (individual) protection for groups at greatest risk of disease.

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).

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.

Increasing awareness and uptake of the MenB vaccine on a large university campus

Objective: At a large public university, we aimed to evaluate an intervention designed to increase serogroup B meningococcal (MenB) vaccine uptake and awareness.Methods: Using a pretest-posttest design with a double posttest, we evaluated an intervention conducted by a local foundation and the Florida Department of Health that distributed MenB vaccine on campus and conducted an educational campaign. Prior to intervention activities, we recruited students to complete a survey about their MenB knowledge and attitudes. For survey participants who provided contact information, we sent two follow-up surveys and assessed MenB vaccine records. We used chi-square tests, adjusted for nonindependence, to compare preintervention to postintervention (three-month and one-year) vaccination and attitudes.Results: Among the 686 students with accessible vaccine records, MenB vaccine initiation increased 9% (from 24% to 33%) and completion increased 8% (from 13% to 21%) from before the intervention to one year after the intervention. When restricting to students who completed the relevant follow-up surveys, the percentage of students who heard of the MenB vaccine increased by 15% (p > .001) from before the intervention to three months after (n = 188 students) and maintained a 10% increase (p > .001) one year after the intervention (n = 261 students). Among students that heard of the MenB vaccine, the percentage of students who thought they needed the MenB vaccine even though they received the MenACWY increased 14% (p = .03) by the three-month postintervention survey and up to 18% by the one-year follow-up (p = .002).Conclusions: A university-wide, on-campus vaccination and educational campaign increased college students' MenB vaccine initiation, completion, and knowledge.Clinicaltrials.gov ID: NCT02975596.

Genetic Diversity of Meningococcal Serogroup B Vaccine Antigens among Carriage Isolates Collected from Students at Three Universities in the United States, 2015-2016

Carriage evaluations were conducted during 2015 to 2016 at two U.S. universities in conjunction with the response to disease outbreaks caused by Neisseria meningitidis serogroup B and at a university where outbreak and response activities had not occurred. All eligible students at the two universities received the serogroup B meningococcal factor H binding protein vaccine (MenB-FHbp); 5.2% of students (181/3,509) at one university received MenB-4C. A total of 1,514 meningococcal carriage isolates were obtained from 8,905 oropharyngeal swabs from 7,001 unique participants. Whole-genome sequencing data were analyzed to understand MenB-FHbp’s impact on carriage and antigen genetic diversity and distribution. Of 1,422 isolates from carriers with known vaccination status (726 [51.0%] from MenB-FHbp-vaccinated, 42 [3.0%] from MenB-4C-vaccinated, and 654 [46.0%] from unvaccinated participants), 1,406 (98.9%) had intact fHbp alleles (716 from MenB-FHbp-vaccinated participants). Of 726 isolates from MenB-FHbp-vaccinated participants, 250 (34.4%) harbored FHbp peptides that may be covered by MenB-FHbp. Genogroup B was detected in 122/1,422 (8.6%) and 112/1,422 (7.9%) isolates from MenB-FHbp-vaccinated and unvaccinated participants, respectively. FHbp subfamily and peptide distributions between MenB-FHbp-vaccinated and unvaccinated participants were not statistically different. Eighteen of 161 MenB-FHbp-vaccinated repeat carriers (11.2%) acquired a new strain containing one or more new vaccine antigen peptides during multiple rounds of sample collection, which was not statistically different (P = 0.3176) from the unvaccinated repeat carriers (1/30; 3.3%). Our findings suggest that lack of MenB vaccine impact on carriage was not due to missing the intact fHbp gene; MenB-FHbp did not affect antigen genetic diversity and distribution during the study period.

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.

Broad vaccine protection against Neisseria meningitidis using factor H binding protein

Neisseria meningitidis, the causative agent of invasive meningococcal disease (IMD), is classified into different serogroups defined by their polysaccharide capsules. Meningococcal serogroups A, B, C, W, and Y are responsible for most IMD cases, with serogroup B (MenB) causing a substantial percentage of IMD cases in many regions. Vaccines using capsular polysaccharides conjugated to carrier proteins have been successfully developed for serogroups A, C, W, and Y. However, because the MenB capsular polysaccharide is poorly immunogenic, MenB vaccine development has focused on alternative antigens. The 2 currently available MenB vaccines (MenB-4C and MenB-FHbp) both include factor H binding protein (FHbp), a surface-exposed protein harboured by nearly all meningococcal isolates that is important for survival of the bacteria in human blood. MenB-4C contains a nonlipidated FHbp from subfamily B in addition to other antigens, including Neisserial Heparin Binding Antigen, Neisserial adhesin A, and outer membrane vesicles, whereas MenB-FHbp contains a lipidated FHbp from each subfamily (A and B). FHbp is highly immunogenic and a main target of bactericidal activity of antibodies elicited by both licensed MenB vaccines. FHbp is also an important vaccine component, in contrast to some other meningococcal antigens that may have limited cross-protection across strains, as FHbp-specific antibodies can provide broad cross-protection within each subfamily. Limited cross-protection between subfamilies necessitates the inclusion of FHbp variants from both subfamilies to achieve broad FHbp-based vaccine coverage. Additionally, immune responses to the lipidated form of FHbp have a superior cross-reactive profile to those elicited by the nonlipidated form. Taken together, the inclusion of lipidated FHbp variants from both FHbp subfamilies is expected to provide broad protection against the diverse disease-causing meningococcal strains expressing a wide range of FHbp sequence variants. This review describes the development of vaccines for MenB disease prevention, with a focus on the FHbp antigen.

Herd Protection against Meningococcal Disease through Vaccination

Reduction in the transmission of Neisseria meningitidis within a population results in fewer invasive disease cases. Vaccination with meningococcal vaccines composed of high weight capsular polysaccharide without carrier proteins has minimal effect against carriage or the acquisition of carriage. Conjugate vaccines, however, elicit an enhanced immune response which serves to reduce carriage acquisition and hinder onwards transmission. Since the 1990s, several meningococcal conjugate vaccines have been developed and, when used in age groups associated with higher carriage, they have been shown to provide indirect protection to unvaccinated cohorts. This herd protective effect is important in enhancing the efficiency and impact of vaccination. Studies are ongoing to assess the effect of protein-based group B vaccines on carriage; however, current data cast doubt on their ability to reduce transmission.

Serogroup B meningococcal vaccination practice patterns on college campuses

BACKGROUND

Most Neisseria meningitidis involved in invasive disease among American college students express serogroup B antigen. The Advisory Committee on Immunization Practices (ACIP) recommends healthcare providers (HCPs) share clinical decision making with patients to determine individual value of meningococcal serogroup B vaccination (MenB) rather than routinely recommend vaccination as with the meningococcal A,C,W,Y vaccine (MenACWY). This study examines the attitudes and practices of HCPs working in college student health centers (SHCs) regarding the recommendation and administration of MenB to students.

METHODS

The study was conducted as an online and phone survey of SHC HCPs from a sample of colleges across the United States between May 2017 and July 2018. Items compared college SHC policies and practices for MenB to those for MenACWY. It also assessed perceived barriers to and facilitators of MenB delivery to students.

RESULTS

Among the 147 respondents, almost 50% more reported their SHC stocked and administered MenACWY (54.1%) than MenB (37%) (p = .004). Almost five times as many colleges required their students receive MenACWY as MenB (53.5% vs. 10.5%, p < .001). A greater percentage requested students to submit records for MenACWY than MenB (77.3% vs. 46.9%, p < .001), and over three times as many tracked student-body coverage rates for MenACWY than MenB (55.6% vs. 15.8%, p < .001). Nearly three quarters of respondents estimated their college's student body MenB coverage rate to be ≤ 10% or were unable to provide any estimate. Factors perceived by over half of the participants as moderate to extreme barriers to administering MenB included high upfront costs for SHCs to purchase and stock MenB (68.7%), and high out-of-pocket costs for students to receive it (82.8%).

CONCLUSIONS

A minority of college SHCs require, offer or track Men B vaccination on their campuses. Financial concerns are common barriers to SHCs' stocking and administering MenB to students.

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.

The epidemiology of invasive meningococcal disease and the utility of vaccination in Malta

Invasive meningococcal disease (IMD) is a vaccine-preventable devastating infection that mainly affects infants, children and adolescents. We describe the population epidemiology of IMD in Malta in order to assess the potential utility of a meningococcal vaccination programme. All cases of microbiologically confirmed IMD in the Maltese population from 2000 to 2017 were analysed to quantify the overall and capsular-specific disease burden. Mean overall crude and age-specific meningococcal incidence rates were calculated to identify the target age groups that would benefit from vaccination. Over the 18-year study period, 111 out of the 245 eligible notified cases were confirmed microbiologically of which 70.3% had septicaemia, 21.6% had meningitis, and 6.3% had both. The mean overall crude incidence rate was 1.49/100,000 population with an overall case fatality rate of 12.6%. Meningococcal capsular groups (Men) B followed by C were the most prevalent with W and Y appearing over the last 6 years. Infants had the highest meningococcal incidence rate of 18.9/100,000 followed by 6.1/100,000 in 1–5 year olds and 3.6/100,000 in 11–15 year old adolescents. The introduction of MenACWY and MenB vaccines on the national immunization schedule in Malta would be expected to reduce the disease burden of meningococcal disease in children and adolescents in Malta.

Insights on Population Structure and Within-Host Genetic Changes among Meningococcal Carriage Isolates from U.S. Universities

In 2015 and 2016, meningococcal carriage evaluations were conducted at two universities in the United States following mass vaccination campaigns in response to Neisseria meningitidis serogroup B (NmB) disease outbreaks. A simultaneous carriage evaluation was also conducted at a university near one of the outbreaks, where no NmB cases were reported and no mass vaccination occurred. A total of ten cross-sectional carriage evaluation rounds were conducted, resulting in 1,514 meningococcal carriage isolates collected from 7,001 unique participants; 1,587 individuals were swabbed at multiple time points (repeat participants). All isolates underwent whole-genome sequencing. The most frequently observed clonal complexes (CC) were CC198 (27.3%), followed by CC1157 (17.4%), CC41/44 (9.8%), CC35 (7.4%), and CC32 (5.6%). Phylogenetic analysis identified carriage isolates that were highly similar to the NmB outbreak strains; comparative genomics between these outbreak and carriage isolates revealed genetic changes in virulence genes. Among repeat participants, 348 individuals carried meningococcal bacteria during at least one carriage evaluation round; 50.3% retained N. meningitidis carriage of a strain with the same sequence type (ST) and CC across rounds, 44.3% only carried N. meningitidis in one round, and 5.4% acquired a new N. meningitidis strain between rounds. Recombination, point mutations, deletions, and simple sequence repeats were the most frequent genetic mechanisms found in isolates collected from hosts carrying a strain of the same ST and CC across rounds. Our findings provide insight on the dynamics of meningococcal carriage among a population that is at higher risk for invasive meningococcal disease than the general population.IMPORTANCE U.S. university students are at a higher risk of invasive meningococcal disease than the general population. The responsible pathogen, Neisseria meningitidis, can be carried asymptomatically in the oropharynx; the dynamics of meningococcal carriage and the genetic features that distinguish carriage versus disease states are not completely understood. Through our analyses, we aimed to provide data to address these topics. We whole-genome sequenced 1,514 meningococcal carriage isolates from individuals at three U.S. universities, two of which underwent mass vaccination campaigns following recent meningococcal outbreaks. We describe the within-host genetic changes among individuals carrying a strain with the same molecular type over time, the primary strains being carried in this population, and the genetic differences between closely related outbreak and carriage strains. Our results provide detailed information on the dynamics of meningococcal carriage and the genetic differences in carriage and outbreak strains, which can inform future efforts to reduce the incidence of invasive meningococcal disease.

Size-Controlled Chemoenzymatic Synthesis of Homogeneous Oligosaccharides of Neisseria meningitidis W Capsular Polysaccharide

Neisseria meningitidis (Nm) serogroup W (NmW) is one of the six meningococcal serogroups that cause majority of invasive meningococcal diseases (IMD). Its capsular polysaccharide (CPS) is a virulence factor and is a key component in NmW CPS-protein conjugate vaccines. The current clinically used NmW CPS-protein conjugate vaccines are effective but the costs are high and the products are heterogeneous at both the CPS and the conjugate levels. Towards the development of potentially better NmW CPS vaccines, herein we report the synthesis of homogeneous oligosaccharides of NmW CPS in a size-controlled manner using polysaccharide synthase NmSiaD_W in a sequential one-pot multienzyme (OPME) platform. Taking advantage of the obtained structurally defined synthetic oligosaccharides tagged with a hydrophobic chromophore, detailed biochemical characterization of NmSiaD_W has been achieved. While the catalytic efficiency of the galactosyltransferase activity of NmSiaD_W increases dramatically with the increase of the sialoside acceptor substrate size, the size difference of the galactoside acceptor substrate does not influence NmSiaD_W sialyltransferase activity significantly. The ratio of donor and acceptor substrate concentrations, but not the size of the acceptor substrates, has been found to be the major determining factor for the sizes of the oligosaccharides produced. NmW CPS oligosaccharides with a degree of polymerization (DP) higher than 65 have been observed. The study provides a better understanding of NmSiaD_W capsular polysaccharide synthase and showcases an efficient chemoenzymatic synthetic platform for obtaining structurally defined NmW CPS oligosaccharides in a size-controlled manner.

Meningococcal B Vaccine and Meningococcal Carriage in Adolescents in Australia

BACKGROUND

The meningococcal group B vaccine 4CMenB is a new, recombinant protein-based vaccine that is licensed to protect against invasive group B meningococcal disease. However, its role in preventing transmission and, therefore, inducing population (herd) protection is uncertain.

METHODS

We used cluster randomization to assign, according to school, students in years 10 to 12 (age, 15 to 18 years) in South Australia to receive 4CMenB vaccination either at baseline (intervention) or at 12 months (control). The primary outcome was oropharyngeal carriage of disease-causing Neisseria meningitidis (group A, B, C, W, X, or Y) in students in years 10 and 11, as identified by polymerase-chain-reaction assays for PorA (encoding porin protein A) and N. meningitidis genogroups. Secondary outcomes included carriage prevalence and acquisition of all N. meningitidis and individual disease-causing genogroups. Risk factors for carriage were assessed at baseline.

RESULTS

A total of 237 schools participated. During April through June 2017, a total of 24,269 students in years 10 and 11 and 10,220 students in year 12 were enrolled. At 12 months, there was no difference in the prevalence of carriage of disease-causing N. meningitidis between the vaccination group (2.55%; 326 of 12,746) and the control group (2.52%; 291 of 11,523) (adjusted odds ratio, 1.02; 95% confidence interval [CI], 0.80 to 1.31; P = 0.85). There were no significant differences in the secondary carriage outcomes. At baseline, the risk factors for carriage of disease-causing N. meningitidis included later year of schooling (adjusted odds ratio for year 12 vs. year 10, 2.75; 95% CI, 2.03 to 3.73), current upper respiratory tract infection (adjusted odds ratio, 1.35; 95% CI, 1.12 to 1.63), cigarette smoking (adjusted odds ratio, 1.91; 95% CI, 1.29 to 2.83), water-pipe smoking (adjusted odds ratio, 1.82; 95% CI, 1.30 to 2.54), attending pubs or clubs (adjusted odds ratio, 1.54; 95% CI, 1.28 to 1.86), and intimate kissing (adjusted odds ratio, 1.65; 95% CI, 1.33 to 2.05). No vaccine safety concerns were identified.

CONCLUSIONS

Among Australian adolescents, the 4CMenB vaccine had no discernible effect on the carriage of disease-causing meningococci, including group B. (Funded by GlaxoSmithKline; ClinicalTrials.gov number, NCT03089086.).

A critical analysis of serogroup B meningococcal disease burden in Brazil (2001-2015): implications for public health decisions

The recent licensure of two different serogroup B recombinant protein meningococcal vaccines in Brazil emphasizes the importance of a better knowledge of the real burden of serogroup B meningococcal (MenB) disease to establish evidence-based vaccination policies. We performed an observational, descriptive study, from 2001 to 2015, analyzing the incidence and case fatality rates (CFR) of MenB disease in Brazil, according to age group and region. In the absence of any vaccine use targeting MenB disease, a significant decline of 90% in the overall incidence rates of MenB disease was observed (from 0.55 cases/100,000 habitants in 2001 to 0.05 in 2015), with declines found in all age groups during the study period. The highest incidence rates were consistently observed in infants and children 1-4 year of age, whereas adults ≥ 60 years experienced the highest CFR (33.9%). The proportion of cases with serogroup identified increased from 37.1% in 2001 to 51.5% in 2015. Despite an improvement in recent years, the quality of diagnosis is highly heterogeneous in the diverse regions, presenting important deficiencies that still prevent the possibility of a robust and reliable analysis of the burden of the meningococcal disease in Brazil. Based on the findings of this study and taking in account the unlikely indirect effect associated with the use of the new recombinant serogroup B protein vaccines, infants < 1 year is the age group to be prioritized when considering the implementation of routine immunization programmes with MenB vaccines.

A review of the immunogenicity, safety and current recommendations for the meningococcal serogroup B vaccine, MenB-FHbp

WHAT IS KNOWN AND OBJECTIVE

This review describes invasive meningococcal disease (IMD) epidemiology in the United States, provides a brief overview of available meningococcal vaccines and discusses meningococcal serogroup B (MenB) vaccine development. Particular focus is given to the recombinant protein MenB vaccine, MenB-FHbp (Trumenba^® , bivalent rLP2086) in light of recent publication of phase 3 data; the other MenB vaccine (Bexsero^® , MenB-4C) has been recently reviewed. Current recommendations of the US Advisory Committee on Immunization Practices (ACIP) for MenB vaccination and potential barriers to immunization are also discussed.

METHODS

Using the published literature, this article reviews the development and use of MenB-FHbp to date, with a focus on the United States.

RESULTS AND DISCUSSION

Despite the availability of medical treatment, IMD is associated with significant mortality and frequently occurring serious permanent sequelae in surviving individuals. Worldwide, most IMD is caused by six serogroups (A, B, C, W, X and Y). MenB is the most common disease-causing meningococcal serogroup in the United States and has caused several recent university-based IMD outbreaks. MenB vaccines, including MenB-FHbp, are available in the United States. ACIP recommends that all individuals ≥10 years of age at increased risk for meningococcal disease receive MenB vaccination; healthy individuals 16-23 years of age are recommended MenB vaccines based on individual clinical decision-making. MenB-FHbp is used on a 2-dose schedule (0, 6 months) when vaccinating healthy individuals and on a tailored 3-dose schedule (0, 1-2, 6 months) in cases of increased risk.

WHAT IS NEW AND CONCLUSION

Because vaccination provides the most effective protection against IMD, pharmacists are in an excellent position to offer evidence-based vaccine information, as well as to encourage and provide meningococcal immunizations to adolescents and young adults.

Meningococcal Group B Vaccine For The Prevention Of Invasive Meningococcal Disease Caused By Neisseria meningitidis Serogroup B

Invasive meningococcal disease (IMD) is a major public health concern because of its high case fatality, long-term morbidity, and potential to course with outbreaks. IMD caused by Nesseira meningitidis serogroup B has been predominant in different regions of the world like Europe and only recently broadly protective vaccines against B serogroup have become available. Two protein-based vaccines, namely 4CMenB (Bexsero^®) and rLP2086 (Trumenba^®) are currently licensed for use in different countries against MenB disease. These vaccines came from a novel technology on vaccine design (or antigen selection) using highly specific antigen targets identified through whole-genome sequence analysis. Moreover, it has the potential to confer protection against non-B meningococcus and against other Neisserial species such as gonococcus. Real-world data on the vaccine-use are rapidly accumulating from the UK and other countries which used the vaccine for control of outbreak or as part of routine immunization program, reiterating its safety and efficacy. Additional data on real-life effectiveness, long-term immunity, and eventual herd effects, including estimates on vaccine impact for cost-effectiveness assessment are further needed. Given the predominance of MenB in Europe and other parts of the world, these new vaccines are crucial for the prevention and public health control of the disease, and should be considered.

Epidemiologic Trends, Global Shifts in Meningococcal Vaccination Guidelines, and Data Supporting the Use of MenACWY-TT Vaccine: A Review

Neisseria meningitidis is a major cause of meningitis and septicemia with cases, outbreaks, and epidemics reported globally in industrialized and non-industrialized countries. N. meningitidis is categorized into 12 serogroups; however, only 5 serogroups (A, B, C, W, Y) are responsible for the majority of disease. Invasive meningococcal disease (IMD) occurs unpredictably; protection is therefore best achieved by initiating proactive vaccination strategies. Vaccines are currently available for the five main disease-causing serogroups. With the evolution of meningococcal vaccines and changes in IMD epidemiology, different vaccination strategies have been used. Recently, the rapid clonal expansion of meningococcal serogroup W (MenW) has been associated with a change in the national and regional vaccination recommendations from monovalent meningococcal serogroup C vaccines to meningococcal serogroup A, C, W, Y (MenACWY) vaccines in several countries. This review highlights these and other changes in IMD epidemiology and meningococcal vaccination recommendations, summarizes information available for currently available conjugate MenACWY vaccines, and focuses on clinical study data for the most recently approved MenACWY conjugate vaccine, MenACWY vaccine conjugated to tetanus toxoid (MenACWY-TT). MenACWY-TT studies spanned multiple age groups and generally demonstrated safety and immunogenicity in comparison with other meningococcal vaccines and under concomitant administration of other routine vaccines. Continuous updates to meningococcal vaccine recommendations in response to changing epidemiology, as have been undertaken for MenW, are necessary to ensure optimal population protection. FUNDING: Pfizer, Inc.

University-Based Outbreaks of Meningococcal Disease Caused by Serogroup B, United States, 2013-2018

We reviewed university-based outbreaks of meningococcal disease caused by serogroup B and vaccination responses in the United States in the years following serogroup B meningococcal (MenB) vaccine availability. Ten university-based outbreaks occurred in 7 states during 2013–2018, causing a total of 39 cases and 2 deaths. Outbreaks occurred at universities with 3,600–35,000 undergraduates. Outbreak case counts ranged from 2 to 9 cases; outbreak duration ranged from 0 to 376 days. All 10 universities implemented MenB vaccination: 3 primarily used MenB-FHbp and 7 used MenB-4C. Estimated first-dose vaccination coverage ranged from 14% to 98%. In 5 outbreaks, additional cases occurred 6–259 days following MenB vaccination initiation. Although it is difficult to predict outbreak trajectories and evaluate the effects of public health response measures, achieving high MenB vaccination coverage is crucial to help protect at-risk persons during outbreaks of meningococcal disease caused by this serogroup.

Carriage prevalence of Neisseria meningitidis in the Americas in the 21st century: a systematic review

Neisseria meningitidis is a bacterium that colonizes the human nasopharynx and is transmitted by respiratory droplets from asymptomatic or symptomatic carriers. Occasionally, the pathogen invades the mucosa and enters the bloodstream, causing invasive meningococcal disease, a life-threatening infection. While meningococcal colonization is the first step in the development of invasive disease, the risk factors that predict progression from asymptomatic to symptomatic status are not well-known. The present report aimed to describe the prevalence of N. meningitidis carriers throughout the Americas, emphasizing the risk factors associated with carrier status, as well as the most prevalent serogroups in each studied population. We conducted a systematic review by searching for original studies in the MEDLINE/PubMed, Embase, LILACS and SciELO databases, published between 2001 and 2018. Exclusion criteria were articles published in a review format, case studies, case control studies, investigations involving animal models, and techniques or publications that did not address the prevalence of asymptomatic carriers in an American country. A total of 784 articles were identified, of which 23 were selected. The results indicate that the highest prevalence rates are concentrated in Cuba (31.9%), the United States (24%), and Brazil (21.5%), with increased prevalence found among adolescents and young adults, specifically university students and males. The present systematic review was designed to support epidemiological surveillance and prevention measures to aid in the formulation of strategies designed to control the transmission of meningococci in a variety of populations and countries throughout the Americas.

Serogroup-specific meningococcal carriage by age group: a systematic review and meta-analysis

OBJECTIVE

Neisseria meningitidis carriage prevalence has known variation across the lifespan, but it is unclear whether carriage varies among meningococcal capsular groups. Therefore, we aimed to characterise group-specific meningococcal carriage by age group and world region from 2007 to 2016.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

MEDLINE, Embase, Global Health Database, WHO Global Health Library, Web of Science, Current Contents Connects, China National Knowledge Infrastructure and Wanfang were systematically searched. Database searches were conducted through July 2018 and Google Scholar forward searches of included studies were conducted through August 2018. References of included studies and relevant conference abstracts were also searched to identify additional articles for inclusion.

ELIGIBILITY CRITERIA

Studies were eligible for inclusion if they reported capsular group-specific meningococcal carriage in a healthy population of a specified age group and geographical region. For this review, only studies conducted between 2007 and 2016 were included.

DATA EXTRACTION AND SYNTHESIS

Data were independently extracted by two authors into Microsoft Access. Studies were assessed for risk of bias using the Joanna Briggs Institute Critical Appraisal Checklist for Studies Reporting Prevalence Data. Studies eligible for inclusion in quantitative analyses by pre-specified age groups were pooled using random effects meta-analyses. Results are reported by capsular group, age group and WHO region. Where meta-analyses were not appropriate, study results were discussed narratively.

RESULTS

7511 articles were identified and 65 were eligible for inclusion. Adolescents and young adults were the focus of many studies (n=24), especially in the Americas and Europe. Studies from China and Africa, typically, included data from a wider age range. The overall carriage prevalence varied markedly by age group and region. Based on the available data, 21 studies were included in meta-analyses reporting serogroup carriage for: all ages in Africa, 18-24-year olds in the Americas, and 11-17 and 18-24-year olds in Europe. Capsular groups W, X, Y and 'other' (non-ABCWXY, including non-groupable) were the most prevalent in Africa, and 5-17-year olds had higher carriage prevalence than other age groups. 'Other' serogroups (11.5%, 95% CI 1.6% to 16.1%) were the most common among 18-24-year olds from the Americas. In Europe, 18-24-year old were carriers more frequently than 11-17-year olds, and groups B (5.0%, 95% CI 3.0% to 7.5%), Y (3.9%, 95% CI 1.3% to 7.8%) and 'other' (6.4%, 95% CI 3.1% to 10.8%) were the most commonly carried in the older age group.

CONCLUSIONS

Of the age groups included in the analysis, carriage patterns by age were similar across capsular groups within a region but differed between regions. Data gaps remain for age- and capsular group-specific carriage in many regions, especially in the Eastern Mediterranean and South-East Asia. As such, clear and robust conclusions about the variation of capsular group-specific carriage by age group and WHO region were unable to be determined.

PROSPERO REGISTRATION NUMBER

CRD42017074671.

Experience implementing a university-based mass immunization program in response to a meningococcal B outbreak

Neisseria meningitidis serogroup B (MenB) has caused several recent outbreaks of meningococcal disease on US college campuses. In January 2015, a case of MenB was reported at a university in Oregon, culminating in an outbreak with a total of 7 cases (including 1 fatality) identified over a 5-month period. In response to the outbreak, the university organized a mass immunization campaign with 4 "opt-in" immunization clinics. The preparation, challenges, and resources required for organization and implementation of a mass immunization program in response to an outbreak at a large public university are discussed herein. Based on the logistical challenges as well as resource expenditures associated with planning and executing a mass immunization effort, this experience illustrates that proactive, routine immunization of incoming students is the best strategy for MenB outbreak prevention.

Meningococcal Disease Among College-Aged Young Adults: 2014-2016

: media-1vid110.1542/5839998266001PEDS-VA_2018-2130Video Abstract BACKGROUND: Freshman college students living in residence halls have previously been identified as being at an increased risk for meningococcal disease. In this evaluation, we assess the incidence and characteristics of meningococcal disease in college-aged young adults in the United States.

METHODS

The incidence and relative risk (RR) of meningococcal disease among college students compared with noncollege students aged 18 to 24 years during 2014-2016 were calculated by using data from the National Notifiable Diseases Surveillance System and enhanced meningococcal disease surveillance. Differences in demographic characteristics and clinical features of meningococcal disease cases were assessed. Available meningococcal isolates were characterized by using slide agglutination, polymerase chain reaction, and whole genome sequencing.

RESULTS

From 2014 to 2016, 166 cases of meningococcal disease occurred in persons aged 18 to 24 years, with an average annual incidence of 0.17 cases per 100 000 population. Six serogroup B outbreaks were identified on college campuses, accounting for 31.7% of serogroup B cases in college students during this period. The RR of serogroup B meningococcal (MenB) disease in college students versus noncollege students was 3.54 (95% confidence interval: 2.21-5.41), and the RR of serogroups C, W, and Y combined was 0.56 (95% confidence interval: 0.27-1.14). The most common serogroup B clonal complexes identified were CC32/ET-5 and CC41/44 lineage 3.

CONCLUSIONS

Although the incidence is low, among 18- to 24-year-olds, college students are at an increased risk for sporadic and outbreak-associated MenB disease. Providers, college students, and parents should be aware of the availability of MenB vaccines.

Costs of Invasive Meningococcal Disease: A Global Systematic Review

BACKGROUND

Invasive meningococcal disease remains a public health concern because of its rapid onset and significant risk of death and long-term disability. New meningococcal serogroup B and combination serogroup ACWY vaccines are being considered for publicly funded immunization programs in many countries. Contemporary costing data associated with invasive meningococcal disease are required to inform cost-effectiveness analyses.

OBJECTIVE

The objective of this study was to estimate costs and resource utilization associated with acute infection and the long-term care of invasive meningococcal disease.

DATA SOURCES AND METHODS

PubMed, EMBASE, The Cochrane Library, health economic databases, and electronically available conference abstracts were searched. Studies reporting any costs associated with acute infection and long-term sequelae of invasive meningococcal disease in English were included. All costs were converted into purchasing power parity-adjusted estimates [international dollars (I$)] using the Campbell and Cochrane Economics Methods Group and the Evidence for Policy and Practice Information and Coordinating Centre cost converter.

RESULTS

Fourteen studies met our eligibility criteria and were included. The mean costs of acute admission ranged from I$1629 to I$50,796, with an incremental cost of I$16,378. The mean length of hospital stay was reported to be 6-18 days in multiple studies. The average costs reported for readmissions ranged from I$7905 to I$15,908. Key variables such as the presence of sequelae were associated with higher hospitalization costs and longer inpatient stay. No studies estimated direct non-healthcare costs and productivity loss. Ten studies reported only unadjusted mean values without using appropriate statistical methods for adjustment.

CONCLUSIONS

Invasive meningococcal disease can result in substantial costs to healthcare systems. However, costing data on long-term follow-up and indirect costs used to populate health economic models are lacking.