Epidemiology of Meningococcal Disease Outbreaks in the United States, 2009-2013

Inequalities in the risk and prevention of invasive meningococcal disease in the United States - A systematic literature review

Vaccination remains the most effective strategy to prevent invasive meningococcal disease (IMD), with MenACWY, MenB and MenABCWY recommended for adolescents/young adults in the United States (US). However, vaccination coverage remains suboptimal, which could be related to population inequalities. To understand the impact of IMD risk, prevention and control inequalities, a global systematic literature review (Medline, Embase, 2012-2022) was conducted on individual, socioeconomic, and environmental inequalities associated with IMD risk, prevention and control in all ages. Studies on IMD risk (n = 15) and prevention (n = 14) inequalities were identified. IMD incidence proportions were higher in Medicaid versus commercially insured populations, and IMD mortality was higher in poorer neighborhoods. White adolescents, adolescents from lower income families, and with lower maternal education were more likely to receive MenB vaccination; while Black and Hispanic adolescents, and adolescents with higher family incomes, were more likely to receive MenACWY vaccination. Meningococcal vaccination was associated with being up-to-date with other vaccinations, having multiple healthcare/well child visits, having a pediatrician as healthcare provider (HCP), and attending private facilities; while being uninsured was associated with lower vaccination. States with a MenACWY vaccination mandate and higher pediatrician-to-children ratios had higher vaccination rates. Important inequalities were due to individual differences, socioeconomic, and environmental factors. IMD prevention is suboptimal, especially among adolescents/young adults. To improve health equity, health policy makers could ameliorate meningococcal vaccination coverage across the US, with simplified and stronger meningococcal vaccine recommendations from public health authorities, and initiatives to enhance parental/patient and HCP knowledge of IMD and vaccine recommendations.

Estimating the cost of university-based outbreaks of serogroup B meningococcal disease with different pre-matriculation vaccination policies in the United States

Objective: We developed an Excel-based cost calculator to assess the economic burden of university-based Neisseria meningitidis serogroup B (MenB) outbreaks. Participants: Hypothetical university with 6,354 students. Methods: Total societal costs of outbreak were estimated for three MenB pre-matriculation immunization policies-vaccination required, vaccination recommended, and no vaccine policy-under three different cost assumptions (low/mid-range/high cost). Results: Mid-range cost estimates of an outbreak under "no policy" were $2.60 and $2.70 million (of which 35% were incurred by the university) if targeting all undergraduates for mass vaccination with a two-/three-dose vaccine, respectively. The "required" and "recommended" policies lowered the burden to $2.17-$2.18 million and $2.34-$2.39 million, respectively. For a larger university with 40,000 students, costs were almost $9 million for a two-dose vaccine with "no policy" in place. Conclusions: The economic burden of a university MenB outbreak is substantial, but could be mitigated by a pre-matriculation MenB vaccination requirement or recommendation.

Quadrivalent Conjugate Vaccine and Invasive Meningococcal Disease in US Adolescents and Young Adults

Importance

Beginning in 2005, the US implemented routine immunization of adolescents with a quadrivalent conjugate vaccine (MenACWY) for the prevention of invasive meningococcal disease (IMD).

Objectives

To assess whether MenACWY immunization was associated with a reduced IMD burden among the US adolescent population and how the downward trajectory of IMD that began in the mid-1990s might have evolved in the absence of vaccination efforts.

Design, Setting, and Participants

In this decision analytical study, a bayesian hierarchical Poisson regression model was developed to investigate the potential trajectory of IMD among US adolescents and young adults without vaccination and evaluate the direct association of vaccination with IMD burden. The model included the entire age-stratified US population and was fitted to national incidence data for serogroups C, W, and Y from January 1, 2001, to December 31, 2021, with stratification by vaccination status for IMD cases.

Intervention

Simulated counterfactual scenario of absent vaccination from 2005 to 2021, while retaining the incidence rate of IMD for unvaccinated individuals estimated during model fitting.

Main Outcomes and Measures

The main outcomes were the estimated numbers of IMD cases and deaths averted by MenACWY vaccination among US adolescents and young adults aged 11 to 23 years.

Results

Among the entire US population from 2005 to 2021, MenACWY vaccination prevented an estimated 172 (95% credible interval [CrI], 85-345) cases of IMD among US adolescents 11 to 15 years of age and 328 (95% CrI, 164-646) cases of IMD among those aged 16 to 23 years. Absent vaccination, the cumulative incidence of IMD in these age groups would have been at least 59% higher than reported over the same period with vaccination. Using case fatality rates of unvaccinated individuals derived from national data, vaccination averted an estimated 16 (95% CrI, 8-31) deaths among adolescents aged 11 to 15 years and 38 (95% CrI, 19-75) deaths among those aged 16 to 23 years.

Conclusions and Relevance

This decision analytical model suggests that the MenACWY vaccination program in the US was associated with a reduced burden of meningococcal disease. Without vaccination, the incidence rates per 100 000 adolescents and young adults would have been substantially higher than those observed during the vaccine era.

Statewide Outbreak of Neisseria meningitidis Serogroup Y, Sequence Type 1466 - Virginia, 2022-2024

Invasive meningococcal disease (IMD) is a severe illness that can have devastating effects; outbreaks are uncommon in the United States. Vaccination is the preferred control measure for IMD outbreaks when a defined population at risk (e.g., college students or persons experiencing homelessness) can be identified. In August 2022, the Virginia Department of Health (VDH) began investigating an IMD outbreak in Virginia's Eastern Health Planning Region, prompted by the detection of four confirmed cases within 8 weeks. Clinical isolates available from three cases were characterized as Neisseria meningitidis serogroup Y, sequence type 1466. A subsequent statewide investigation identified 36 genetically related cases, including seven deaths (case fatality rate = 19.4%) as of March 1, 2024. A majority of patients (63.9%) were in an age group (30-60 years) not generally considered at increased risk for IMD; 78.0% were non-Hispanic Black or African American. No common exposures, affiliations, or risk factors were identified, and a defined population could not be identified for vaccination. VDH recommended quadrivalent (serogroups A, C, W, and Y) meningococcal conjugate vaccination of a subset of close contacts of patients based on IMD risk factors and age range similar to that of patients with identified cases. IMD outbreaks might affect populations without established IMD risk factors. Lack of a well-defined population at risk might prompt exploration of novel control strategies, such as selective vaccination of close contacts.

Past, present, and future policy considerations regarding meningococcal vaccination in the United States

INTRODUCTION

In 2005, the United States Advisory Committee on Immunization Practices (ACIP) recommended routine vaccination against invasive meningococcal disease (IMD) caused by serogroups A, C, W, and Y (MenACWY) for all 11-12-year-olds, as well as 2-10-year-olds at high risk. In 2010, a booster dose was recommended for all 16-year-olds, as well as for high-risk patients every 3-5 years. In 2015, optional (as opposed to routine) vaccination against meningococcal serogroup B (MenB) at the preferred age of 16-18 years was recommended (Category B, later changed to shared clinical decision-making). In 2023, a vaccine (MenABCWY) against the five serogroups primarily responsible for IMD in the U.S. became available.

AREAS COVERED

This review summarizes the evolution of public policy that led to each milestone vaccine recommendation, reviews epidemiologic data published following the recommendations, and discusses the current state of meningococcal immunization policy.

EXPERT OPINION

The use of MenABCWY has the potential to consolidate policy, improve coverage rates for the five serogroups, address disparities in vaccination coverage, and simplify vaccine delivery.

Prevention of Neisseria gonorrhoeae With Meningococcal B Vaccine: A Matched Cohort Study in Southern California

BACKGROUND

Neisseria gonorrhoeae is acquiring increasing resistance to available oral antibiotics, and current screening and treatment approaches have not decreased gonorrhea incidence. Although a gonorrhea-specific vaccine does not exist, N. gonorrhoeae shares much of its genome with Neisseria meningitidis, notably critical antigenic determinants including outer membrane vesicles (OMV). Prior observational studies have suggested that OMV-based meningococcal serogroup B vaccines confer protection against gonorrhea.

METHODS

We conducted a matched cohort study from 2016 to 2020 to examine the association of OMV-containing recombinant meningococcal serogroup B vaccine (4CMenB) with gonorrhea infection among teens and young adults at Kaiser Permanente Southern California. Recipients of 4CMenB were matched in a ratio of 1:4 to recipients of non-OMV-containing polysaccharide-conjugate vaccine targeting serotypes A, C, W, and Y (MenACWY) who had not received 4CMenB and were followed for incident gonorrhea. We used Cox proportional hazards regression to compare gonorrhea rates among recipients of 4CMenB vs MenACWY, adjusting for potential confounders. We conducted the same analysis with chlamydia as a negative control outcome.

RESULTS

The study included 6641 recipients of 4CMenB matched to 26 471 recipients of MenACWY. During follow-up, gonorrhea incidence rates per 1000 person-years (95% confidence intervals [CIs]) were 2.0 (1.3-2.8) for recipients of 4CMenB and 5.2 (4.6-5.8) for recipients of MenACWY. In adjusted analyses, gonorrhea rates were 46% lower among recipients of 4CMenB vs MenACWY (hazard ratio [HR], 0.54; 95% CI, .34-.86), but chlamydia rates were similar between vaccine groups (HR, 0.98; 95% CI, .82-1.17).

CONCLUSIONS

These results suggest cross-protection of 4CMenB against gonorrhea, supporting the potential for vaccination strategies to prevent gonorrhea.

The Impact of Social Determinants of Health on Meningococcal Vaccination Awareness, Delivery, and Coverage in Adolescents and Young Adults in the United States: A Systematic Review

Vaccines remain a fundamental intervention for preventing illness and death. In the United States, suboptimal vaccine uptake in adolescents and young adults has been observed for meningococcal conjugate (MenACWY) and serogroup B meningococcal (MenB) vaccines, particularly among marginalized communities, despite current recommendations by the Advisory Committee on Immunization Practices. A systematic literature search was conducted in the MEDLINE and MEDLINE In-Process, Embase, Cochrane, PsychInfo, and CINAHL databases to identify both drivers of, and barriers to, MenACWY and MenB vaccine uptake in adolescents and young adults. A total of 34 of 46 eligible studies that presented outcomes stratified by race/ethnicity, geography, and socioeconomic status were selected for review. Results showed MenACWY and MenB vaccination coverage in adolescents and young adults is impacted by racial/ethnic, socioeconomic, and geographic disparities. Gaps also exist in insurance for, or access to, these vaccines in adolescents and young adults. Moreover, there was variability in the understanding and implementation of the shared decision-making recommendations for the MenB vaccine. Disease awareness campaigns, increased clarity in accessing all meningococcal vaccines, and further research on the relationships between measures of marginalization and its impact on vaccine coverage in adolescents and young adults are needed to reduce the incidence of severe infections.

Meningococcal disease in North America: Updates from the Global Meningococcal Initiative

This review summarizes the recent Global Meningococcal Initiative (GMI) regional meeting, which explored meningococcal disease in North America. Invasive meningococcal disease (IMD) cases are documented through both passive and active surveillance networks. IMD appears to be decreasing in many areas, such as the Dominican Republic (2016: 18 cases; 2021: 2 cases) and Panama (2008: 1 case/100,000; 2021: <0.1 cases/100,000); however, there is notable regional and temporal variation. Outbreaks persist in at-risk subpopulations, such as people experiencing homelessness in the US and migrants in Mexico. The recent emergence of β-lactamase-positive and ciprofloxacin-resistant meningococci in the US is a major concern. While vaccination practices vary across North America, vaccine uptake remains relatively high. Monovalent and multivalent conjugate vaccines (which many countries in North America primarily use) can provide herd protection. However, there is no evidence that group B vaccines reduce meningococcal carriage. The coronavirus pandemic illustrates that following public health crises, enhanced surveillance of disease epidemiology and catch-up vaccine schedules is key. Whole genome sequencing is a key epidemiological tool for identifying IMD strain emergence and the evaluation of vaccine strain coverage. The Global Roadmap on Defeating Meningitis by 2030 remains a focus of the GMI.

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

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

Disease-Specific Health Disparities: A Targeted Review Focusing on Race and Ethnicity

Background: Wide disparities in health status exist in the United States across race and ethnicity, broadly driven by social determinants of health—most notably race and ethnic group differences in income, education, and occupational status. However, disparities in disease frequency or severity remain underappreciated for many individual diseases whose distribution in the population varies. Such information is not readily accessible, nor emphasized in treatment guidelines or reviews used by practitioners. Specifically, a summary on disease-specific evidence of disparities from population-based studies is lacking. Our goal was to summarize the published evidence for specific disease disparities in the United States so that this knowledge becomes more widely available “at the bedside”. We hope this summary stimulates health equity research at the disease level so that these disparities can be addressed effectively. Methods: A targeted literature review of disorders in Pfizer’s current pipeline was conducted. The 38 diseases included metabolic disorders, cancers, inflammatory conditions, dermatologic disorders, rare diseases, and infectious targets of vaccines under development. Online searches in Ovid and Google were performed to identify sources focused on differences in disease rates and severity between non-Hispanic Whites and Black/African Americans, and between non-Hispanic Whites and Hispanics. As a model for how this might be accomplished for all disorders, disparities in disease rates and disease severity were scored to make the results of our review most readily accessible. After primary review of each condition by one author, another undertook an independent review. Differences between reviewers were resolved through discussion. Results: For Black/African Americans, 29 of the 38 disorders revealed a robust excess in incidence, prevalence, or severity. After sickle cell anemia, the largest excesses in frequency were identified for multiple myeloma and hidradenitis suppurativa. For Hispanics, there was evidence of disparity in 19 diseases. Most notable were metabolic disorders, including non-alcoholic steatohepatitis (NASH). Conclusions: This review summarized recent disease-specific evidence of disparities based on race and ethnicity across multiple diseases, to inform clinicians and health equity research. Our findings may be well known to researchers and specialists in their respective fields but may not be common knowledge to health care providers or public health and policy institutions. Our hope is that this effort spurs research into the causes of the many disease disparities that exist in the United States.

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.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

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).

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.

Perceptions and Knowledge About the MenB Vaccine Among Parents of High School Students

Serogroup B meningococcal disease (MenB) causes almost 60% of meningitis cases among adolescents and young adults. Yet, MenB vaccine coverage among adolescents remains below 10%. Since parents are the primary medical decision makers for adolescents, we examined MenB vaccination rates and parent attitudes about meningitis and the MenB vaccine. In 2018, in conjunction with a county-wide, school-based immunization campaign, we conducted a mixed methods study among parents of 16- to 17-year-olds. We facilitated focus groups asking parents about their knowledge of meningitis and reactions to educational materials and sent behavioral surveys based on Health Belief Model constructs to parents through the county high school system. Parents in three focus groups (n = 8; participation rate = 13%) expressed confusion about their child's need to receive the MenB vaccine in addition to the meningococcal conjugate vaccine (MenACWY), but conveyed strong trust in their physicians' recommendation. Among survey participants (n = 170), 70 (41%) had heard of the MenB vaccine. Among those 70 parents, the most common barriers to vaccination were concerns about side effects (55%) and uncertainty of susceptibility due to receipt of the MenACWY vaccine (30%). The percentage of teens that received at least one dose of the MenB vaccine was 50% (n = 35) by parent report and 23% (n = 16) by state vaccination records. Parents demonstrated uncertainty and confusion about the MenB vaccine particularly due to the existence of another meningitis vaccine and limited health care provider recommendations. Confirmatory studies of parent confusion about the MenB vaccine are needed to develop interventions.

Impact of Meningococcal B (4CMenB) Vaccine on Pharyngeal Neisseria meningitidis Carriage Density and Persistence in Adolescents

BACKGROUND

Higher density of Neisseria meningitidis carriage may be associated with transmission of the meningococcus. Our aim was to establish the impact of meningococcal B (4CMenB) vaccine on N. meningitidis carriage density.

METHODS

We compared 4CMenB vaccine to control among 913 South Australian students aged approximately 15-18 years in a cluster randomized trial who had N. meningitidis carriage at 12 months. Oropharyngeal swabs were collected at baseline and 12 months later to detect N. meningitidis carriage. Colony-forming units per milliliter (CFU/mL) were estimated by generating a standard curve that plotted quantitative polymerase chain reaction cycle threshold values against log-normalized CFU.

RESULTS

Among the 913 students with N. meningitidis carriage at 12 months, there was no difference in mean carriage density between the vaccinated (n = 434; 3.80 log CFU/mL [standard deviation {SD}, 1.29]) and control group (n = 479; 3.73 log CFU/mL [SD, 1.30]; P = .51). Higher N. meningitidis carriage density at baseline was associated with an increase in the odds of persistent carriage at 12 months (n = 504; odds ratio [OR] per 1.0 log CFU/mL increase in density, 1.36 [95% confidence interval {CI}, 1.17-1.58]; P < .001). Students with baseline carriage who were vaccinated had decreased persistent N. meningitidis carriage at 12 months compared to unvaccinated students (81/260 [31%] vs 105/244 [43%]; OR, 0.60 [95% CI, .40-.90]; P = .01).

CONCLUSIONS

4CMenB vaccine did not reduce carriage density of N. meningitidis 12 months postvaccination, despite increased carriage clearance. Higher carriage density is likely to enable transmission through prolonged periods of population exposure.

CLINICAL TRIALS REGISTRATION

NCT03089086.

Using Neisseria meningitidis genomic diversity to inform outbreak strain identification

Meningococcal disease is a life-threatening illness caused by the human-restricted bacterium Neisseria meningitidis. Outbreaks in the USA involve at least two cases in an organization or community caused by the same serogroup within three months. Genome comparisons, including phylogenetic analysis and quantification of genome distances can provide confirmatory evidence of pathogen transmission during an outbreak. Interpreting genome distances depends on understanding their distribution both among isolates from outbreaks and among those not from outbreaks. Here, we identify outbreak strains based on phylogenetic relationships among 141 N. meningitidis isolates collected from 28 outbreaks in the USA during 2010-2017 and 1516 non-outbreak isolates collected through contemporaneous meningococcal surveillance. We show that genome distance thresholds based on the maximum SNPs and allele distances among isolates in the phylogenetically defined outbreak strains are sufficient to separate most pairs of non-outbreak isolates into separate strains. Non-outbreak isolate pairs that could not be distinguished from each other based on genetic distances were concentrated in the clonal complexes CC11, CC103, and CC32. Within each of these clonal complexes, phylodynamic analysis identified a group of isolates with extremely low diversity, collected over several years and multiple states. Clusters of isolates with low genetic diversity could indicate increased pathogen transmission, potentially resulting in local outbreaks or nationwide clonal expansions.

Implementation Experience With Meningococcal Serogroup B Vaccines in the United States: Impact of a Nonroutine Recommendation

BACKGROUND

Meningococcal serogroup B (MenB) is the leading cause of invasive meningococcal disease among US adolescents and young adults, accounting for 62% of cases in 16-23-year-olds in 2018. Since 2015, the Advisory Committee on Immunization Practices (ACIP) has recommended vaccination of healthy adolescents against MenB based on shared clinical decision-making (previously called "Category B" or individual clinical decision-making). However, MenB vaccine coverage and series completion rates remain low. Herein we examine implementation experience of adolescent MenB vaccination in the United States under this nonroutine ACIP recommendation.

METHODS

PubMed was searched for English-language articles published after 2015 examining MenB vaccination implementation in the United States. Studies reporting MenB vaccination awareness, coverage, knowledge of recommendations and implementation barriers or access disparities were included.

RESULTS

Identified studies provided evidence that ACIP's MenB vaccination recommendation is poorly understood and prone to misinterpretation by US healthcare providers. Parental awareness of MenB vaccines is low, and racial and socioeconomic disparities exist regarding vaccine receipt. Parents rely on providers to learn about MenB disease risk and benefits of vaccination, with provider recommendations carrying substantial weight in vaccination decisions.

CONCLUSIONS

Five years of evidence regarding the MenB vaccination implementation experience suggest that the nonstandard recommendation for MenB vaccines is partly responsible for low vaccine coverage. Further, inconsistent implementation of ACIP recommendations could be limiting access to MenB vaccines. Providers need additional support and guidance to implement the shared clinical decision-making recommendation, in turn ensuring equitable access for vaccine-eligible adolescents to enable comprehensive protection against meningococcal disease.

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.

Health Technology Assessment for Vaccines Against Rare, Severe Infections: Properly Accounting for Serogroup B Meningococcal Vaccination's Full Social and Economic Benefits

The high price of new generations of vaccines relative to their predecessors has become an important consideration in debates over whether the benefits of the new vaccines justify their costs. An increasingly central line of inquiry in the literature on valuing vaccination surrounds accounting for the full social and economic benefits of vaccination. This paper applies this emerging perspective to the particular case of vaccination against serogroup B meningococcal disease (MenB). We explore key issues involved in health technology assessments of MenB vaccination, which have led to pronounced heterogeneity in evaluation methods and recommendation outcomes across countries such as France, Germany, the US, and the UK. Accounting for typically neglected sources of socioeconomic benefit could potentially impact recommendation and reimbursement decisions. We propose a taxonomy of such benefits built around four dimensions: (i) internalized health benefits, (ii) internalized non-health benefits, (iii) externalized health benefits, and (iv) externalized non-health benefits. This approach offers a systematic, comprehensive evaluation framework that can be used in future assessment of MenB vaccines as well as other health technologies.

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.

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.

Meningococcal pneumonia: a review

Background

Although Neisseria meningitidis is one of the major causes of meningitis, meningococcal pneumonia is the most common non-neurological organ disease caused by this pathogen.

Methods

We conducted a review of the literature to describe the risk factors, pathogenesis, clinical features, diagnosis, treatment and prevention of meningococcal pneumonia.

Results

Meningococcal pneumonia was first described in 1907 and during the 1918–1919 influenza pandemic large numbers of cases of meningococcal pneumonia occurred in patients following the initial viral infection. A number of publications, mainly case series or case reports, has subsequently appeared in the literature. Meningococcal pneumonia occurs mainly with serogroups Y, W-135 and B. Risk factors for meningococcal pneumonia have not been well characterised, but appear to include older age, smoking, people living in close contact (e.g. military recruits and students at university), preceding viral and bacterial infections, haematological malignancies, chronic respiratory conditions and various other non-communicable and primary and secondary immunodeficiency diseases. Primary meningococcal pneumonia occurs in 5–10% of patients with meningococcal infection and is indistinguishable clinically from pneumonia caused by other common pathogens. Fever, chills and pleuritic chest pain are the most common symptoms, occurring in > 50% of cases. Productive sputum and dyspnoea are less common. Diagnosis of meningococcal pneumonia may be made by the isolation of the organism in sputum, blood, or normally sterile site cultures, but is likely to underestimate the frequency of meningococcal pneumonia. If validated, PCR-based techniques may be of value for diagnosis in the future. While penicillin was the treatment of choice for meningococcal infection, including pneumonia, prior to 1991, a third generation cephalosporin has been more commonly used thereafter, because of concerns of penicillin resistance. Chemoprophylaxis, using one of a number of antibiotics, has been recommended for close contacts of patients with meningococcal meningitis, and similar benefits may be seen in contacts of patients with meningococcal pneumonia. Effective vaccines are available for the prevention of infection with certain meningococcal serogroups, but this field is still evolving.

Conclusion

Meningococcal pneumonia occurs fairly frequently and should be considered as a possible cause of pneumonia, particularly in patients with specific risk factors.

Optimizing the timing of 4CMenB vaccination in adolescents and young adults based on immune persistence and booster response data

INTRODUCTION

Meningococcal disease has an incidence peak spread over several years during adolescence and young adulthood in the United States. Meningococcal serogroup B (MenB) vaccines have been introduced relatively recently and may help protect individuals in these age groups. Currently there is insufficient long-term experience to determine the duration of disease protection after any MenB vaccine. Understanding antibody persistence after primary vaccination and responses to booster can help inform MenB vaccination strategies and optimize disease prevention. Areas covered: Four studies in adolescents/young adults vaccinated with meningococcal B vaccine 4CMenB were reviewed with the aim to compare findings across studies and draw key learnings. The studies varied by geographic location, population characteristics, and timing of antibody measurement relative to primary vaccination. Expert opinion: Antibody persistence data for 4CMenB are substantial, extending 7.5 years post-primary vaccination. Vaccination at age 16-18 years may help protect adolescents throughout their highest age-based risk period. Similar robust responses to a single booster dose were observed 4 and 7.5 years after primary vaccination. In outbreak settings it is beneficial to have received prior vaccination; residual circulating antibodies may provide protection, and a single dose induces booster responses within 7 days, which is quicker than administration of a 2-dose series to vaccine-naïve individuals.

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.

Parental awareness of Meningococcal B vaccines and willingness to vaccinate their teens

Background:

In the US, Meningococcal B (MenB) vaccines were first licensed in 2014. In 2015, the Advisory Committee on Immunization Practices recommended that parents of teens talk to their provider about receiving MenB vaccine, rather than issuing a routine recommendation. We assessed parental awareness of MenB vaccines and willingness to vaccinate their teens with MenB vaccines compared to MenACWY vaccines, which have been routinely recommended for many years.

Methods:

We surveyed parents of teens attending high school in 2017–18 during the Minnesota State Fair. Parents reported via iPad their knowledge of and concern about meningococcal disease and their awareness of and willingness to vaccinate with MenB and MenACWY vaccines. We assessed the relationship between meningococcal disease knowledge and concern, MenB and MenACWY vaccine awareness, and willingness to vaccinate with MenB and MenACWY using adjusted logistic regression.

Results:

Among 445 parents, the majority had not heard of the newly introduced MenB vaccines Bexsero^® (80.0%; 95% CI: 76.0–83.6) or Trumenba^® (82.0%; 95% CI: 78.1–85.5) or the MenACWY vaccines Menactra^® or Menveo^® (68.8%; 95% CI: 64.2–73.0). The majority were at least somewhat willing to vaccinate their teen with MenB vaccine (89.6%; 95% CI: 86.5, 92.3) and MenACWY vaccine (91.2%; 95% CI: 88.2, 93.7). Awareness of MenB vaccines (OR: 3.8; 95% CI: 1.2–12.2) and concern about meningococcal disease (OR: 3.1; 95% CI: 1.5–6.3) were significantly associated with willingness to vaccinate with MenB vaccine.

Conclusions:

Awareness of MenB vaccine is lacking among parents of teens but is an important predictor of willingness to vaccinate with the newly licensed MenB vaccines.