BACKGROUND: Invasive meningococcal disease (IMD) is a severe and life-threatening disease. In the United States (US), vaccine coverage with MenACWY and MenB meningococcal vaccines is suboptimal among adolescents/young adults aged 16-23 years. A combined meningococcal vaccine (MenABCWY) could increase convenience (e.g., fewer injections) and improve coverage. The objective was to quantify preferences for hypothetical meningococcal vaccine profiles among adolescents/young adults and parents.
METHODS: An online discrete choice experiment was conducted among 16- to 23-year-olds, and parents of 16- to 18-year-olds. Attributes (3 × 4) and levels (1 × 2) were based on the literature and focus groups. Participants made ten pair-wise forced trade-off choices, systematically varied using a D-optimal design. Random parameter logit quantified the relative importance of vaccination attributes and estimated the trade-offs. Differences in preferences by subgroups were assessed.
RESULTS: Totals of 300 adolescents and young adults (median age 20 years) and 300 parents (median age 46 years) completed the survey. Overall, 89.6% of 16- to 23-year-olds and 69.1% of parents preferred a simplified hypothetical meningococcal vaccination profile, e.g., with fewer injections (3 vs. 4) and fewer healthcare provider (HCP) visits (2-3 vs. 4). Having HCP advice and clear Centers for Disease Control and Prevention recommendations impacted vaccination choice, with both groups reporting high trust in HCP information (83.3% among 16- to 23-year-olds; 98.7% among parents). Barriers to vaccination included lack of HCP advice or awareness of meningococcal vaccines, and income level and out-of-pocket costs for parents.
CONCLUSIONS: Adolescents/young adults and parents demonstrated a significant preference for a meningococcal vaccine that is more convenient (such as combined MenABCWY). Parents\' vaccination preferences differed by income level and out-of-pocket costs, suggesting financial barriers to vaccination may exist which could result in IMD prevention inequalities. Findings from this study provide important information to support patient-facing informed policy discussions. A simplified vaccination schedule and strong recommendation could help improve vaccine uptake, schedule compliance, disease prevention, and reduce inequalities in IMD risk and prevention. A graphical abstract is available with this article.

BACKGROUND: In the United States (US), three types of vaccines are available to prevent invasive meningococcal disease (IMD), a severe and potentially fatal infection: quadrivalent conjugate vaccines against serogroups A, C, W, Y (MenACWY), and monovalent vaccines against serogroup B (MenB) as well as a newly licensed pentavalent vaccine (MenABCWY) protecting against serogroup A, B, C, W, and Y. The CDC\'s Advisory Committee on Immunization Practices (ACIP) routinely recommends MenACWY vaccine for all 11- to 12-year-olds with a booster dose at 16 years. MenB vaccination is recommended based on shared clinical decision-making (SCDM) for 16- to 23-year-olds. Recently, the pentavalent meningococcal vaccine (MenABCWY) was recommended by the ACIP. Meningococcal vaccine uptake is suboptimal across the country, particularly among individuals with lower socioeconomic status (SES), despite these recommendations. The objective of the spatial analyses was to assess the relationship between stocking of MenACWY and MenB vaccines, area-level SES, and state-level policies.
METHODS: The number of MenACWY and MenB doses stocked by vaccinators was obtained from IQVIA and the CDC\'s Vaccine for Children (VFC) program and compiled into a county-level dataset from 2016 to 2019. SES, as measured using the CDC\'s Social Vulnerability Index (SVI), state-level school recommendations, and universal purchasing programs were among the main county-level covariates included to control for factors likely influencing stocking. Data were stratified by public and private market. Bayesian spatial regression models were developed to quantify the variations in rates of stocking and the relative rates of stocking of both vaccines.
RESULTS: After accounting for county-level characteristics, lower SES counties tended to have fewer doses of MenB relative to MenACWY on both public and private markets. Lower SES counties tended to have more supply of public vs. private doses. Universal purchasing programs had a strong effect on the markets for both vaccines shifting nearly all doses to the public market. School vaccination strategy was key for improving stocking rates.
CONCLUSIONS: Overall, the results show that MenACWY has greater stock relative to MenB across the US. This difference is exacerbated in vulnerable areas without school entry requirements for vaccination and results in inequity of vaccine availability. Beyond state-level policy and SES differences, SCDM recommendations may be a contributing factor, although this was not directly assessed by our model.

BACKGROUND: Many immunization programs in Europe recommend quadrivalent meningococcal vaccinations, which are often administered concomitantly with other vaccines. We compared the immune response of a tetanus toxoid conjugated quadrivalent meningococcal vaccine (MenACYW-TT, MenQuadfi®) with another quadrivalent meningococcal conjugate vaccine (MCV4-TT; Nimenrix®) when administered alone or concomitantly with Tdap-IPV and 9vHPV vaccines in adolescents.
METHODS: In this phase IIIb trial, healthy adolescents (MenC-naïve or MenC-primed before 2 years of age) from Spain, Italy, Hungary, and Singapore were randomized in a 3:3:2 ratio to receive either MenACYW-TT or MCV4-TT alone, or MenACYW-TT concomitantly with 9vHPV and Tdap-IPV. The primary objective was to demonstrate the non-inferiority of the seroprotection rate (human serum bactericidal assay [hSBA] titer ≥ 1:8) to serogroups A, C, W, and Y 30 days post-vaccination with a single dose of MenACYW-TT or MCV4-TT. Secondary objectives included describing hSBA titers for the four serogroups before and 1 month following vaccination and according to MenC priming status.
RESULTS: A total of 463 participants were enrolled (MenACYW-TT, n = 173; MCV4-TT, n = 173; MenACYW-TT/9vHPV/Tdap-IPV n = 117). Non-inferiority based on seroprotection was demonstrated for MenACYW-TT versus MCV4-TT for all serogroups. Immune responses were comparable whether MenACYW-TT was administered alone or concomitantly with Tdap-IPV and 9vHPV. Post-vaccination hSBA GMTs were higher in MenACYW-TT vs. MCV4-TT for serogroups C, Y, and W and comparable for serogroup A. The percentages of participants with an hSBA vaccine seroresponse were higher in MenACYW-TT vs. MCV4-TT for all serogroups. For serogroup C, higher GMTs were observed in both MenC-naïve or -primed participants vaccinated with MenACYW-TT vs. MCV4-TT. Seroprotection and seroresponse were higher in MenC-naïve participants vaccinated with MenACYW-TT vs. MCV4-TT and comparable in MenC-primed. The safety profiles were comparable between groups and no new safety concerns were identified.
CONCLUSIONS: These data support the concomitant administration of MenACYW-TT with 9vHPV and Tdap-IPV vaccines in adolescents.
BACKGROUND: Clinicaltrials.gov, NCT04490018; EudraCT: 2020-001665-37; WHO: U1111-1249-2973.
MenACYW conjugate vaccine has been made to protect against meningococcal disease caused by four common types of bacteria (germs) called Neisseria meningitidis (or meningococcus), A, C, W, and Y. Many people, particularly adolescents, have the germs of this disease in their nose or throat, and therefore may develop the disease or transmit the bacteria to other people. Hence, adolescent meningococcal vaccination against serogroups ACWY is increasingly recommended in several countries. This study assessed the immune response to these serogroups in healthy adolescents after one dose of MenACYW conjugate vaccine or Nimenrix®, a meningococcal licensed vaccine. Moreover, the immune response and safety were assessed when the vaccines were given alone or when given concomitantly with other adolescent vaccines, including the human papillomavirus (9vHPV) and tetanus, diphtheria, pertussis, and poliomyelitis (Tdap-IPV) vaccines. A total of 463 adolescents (aged 10–17 years) participated in this study and received either MenACYW or Nimenrix® alone, or MenACYW concomitantly with 9vHPV and Tdap-IPV vaccine. The immune response induced by MenACYW was as good as the immune response induced by Nimenrix®, and when given alone or concomitantly with 9vHPV and Tdap IPV vaccines. None of the participants experienced any serious side effects of any vaccine. The most common non-serious side effects were injection site pain, muscle pain, and headache. These data support the use of MenACYW in adolescents, with or without concomitant administration with 9vHPV and Tdap-IPV, which may help to increase the number of adolescents vaccinated.

BACKGROUND: Invasive meningococcal disease (IMD) cases declined upon the implementation of non-pharmaceutical interventions (NPI) (social distancing and mask wearing) to control the COVID-19 pandemic but rebounded in 2022 in numbers with genotypical changes of the strains. We explored here associated modifications in the clinical presentations of IMD.
METHODS: We conducted a retrospective descriptive study using the Database of the French National Reference Centre for meningococci and Haemophilus influnezae for IMD cases between 2015 and 2022. We scored serogroups, sex, age groups, clinical presentations and clonal complexes of the corresponding patients and isolates.
RESULTS: Non-meningeal forms of IMD increased significantly upon easing of NPI, such as bacteremic meningococcal pneumonia and bacteremic abdominal forms. They represented 6% and 8% of all IMD forms and were significantly linked to serogroups Y and W respectively, to older adults for bacteremic pneumonia and to young adults for bacteremic abdominal presentations. These forms were significantly associated with more early mortality and clonal complexes 23, 11 and 9316.
CONCLUSIONS: The increase in atypical IMD forms may lead to higher burden of IMD due to delayed diagnosis and management. Updating prevention may be needed through by adapting the current vaccination strategies to epidemiological changes.

BACKGROUND: Data on the health-related quality of life (HRQoL) for invasive meningococcal disease (IMD) survivors, particularly among adolescents and young adults (AYAs), are limited. This study aimed to investigate the in-depth experiences and impacts of IMD on AYAs.
METHODS: Participants were recruited from two Australian states, Victoria and South Australia. We conducted qualitative, semi-structured interviews with 30 patients diagnosed with IMD between 2016 and 2021. The interview transcripts were analyzed thematically.
RESULTS: Of the participants, 53% were aged 15-19 years old, and 47% were aged 20-24. The majority (70%) were female. Seven themes relating to the participants\' experience of IMD were identified: (1) underestimation of the initial symptoms and then rapid escalation of symptoms; (2) reliance on social support for emergency care access; (3) the symptoms prompting seeking medical care varied, with some key symptoms missed; (4) challenges in early medical diagnosis; (5) traumatic and life-changing experience; (6) a lingering impact on HRQoL; and (7) gaps in the continuity of care post-discharge.
CONCLUSIONS: The themes raised by AYA IMD survivors identify multiple areas that can be addressed during their acute illness and recovery. Increasing awareness of meningococcal symptoms for AYAs may help reduce the time between the first symptoms and the first antibiotic dose, although this remains a challenging area for improvement. After the acute illness, conducting HRQoL assessments and providing multidisciplinary support will assist those who require more intensive and ongoing assistance during their recovery.

OBJECTIVE: Invasive meningococcal disease (IMD) is a devastating condition. While most attention is directed towards disease in children and adolescents, IMD poses an important cause of morbidity and mortality in adults ≥60 years. While immunization is a critical component of healthy ageing strategies, meningococcal immunization is not routinely offered to older adults. The aim of this review was to summarize clinical and epidemiological aspects of IMD and available immunization strategies, with a particular focus on disease in older individuals, to emphasize the importance of this rather neglected area.
METHODS: An expert working group was established to evaluate clinical and epidemiological data to raise awareness of IMD in older individuals, and develop suggestions to improve the existing burden.
RESULTS: Routine child and adolescent meningococcal immunization has substantially reduced IMD in these targeted populations. Consequently, prevalence and proportion of IMD among those ≥60 years, mostly unvaccinated, is increasing in developed countries (accounting for up to 25% of cases). IMD-related mortality is highest in this age-group, with substantial sequelae in survivors. IMD due to serogroups W and Y is more prevalent among older adults, often with atypical clinical features (pneumonia, gastrointestinal presentations) which may delay timely treatment.
CONCLUSIONS: IMD in older adults remains overlooked and greater awareness is required at clinical and societal levels. We encourage clinicians and immunization policy makers to reconsider IMD, with a call for action to remedy existing inequity in older adult access to protective meningococcal immunization.

BACKGROUND: Invasive meningococcal isolates in South Africa have in previous years (<2008) been characterized by serogroup B, C, W and Y lineages over time, with penicillin intermediate resistance (peni) at 6%. We describe the population structure and genomic markers of peni among invasive meningococcal isolates in South Africa, 2016-2021.
METHODS: Meningococcal isolates were collected through national, laboratory-based invasive meningococcal disease (IMD) surveillance. Phenotypic antimicrobial susceptibility testing and whole-genome sequencing were performed, and the mechanism of reduced penicillin susceptibility was assessed in silico.
RESULTS: Of 585 IMD cases reported during the study period, culture and PCR-based capsular group was determined for 477/585 (82%); and 241/477 (51%) were sequenced. Predominant serogroups included NmB (210/477; 44%), NmW (116/477; 24%), NmY (96/477; 20%) and NmC (48/477; 10%). Predominant clonal complexes (CC) were CC41/44 in NmB (27/113; 24%), CC11 in NmW (46/56; 82%), CC167 in NmY (23/44; 53%), and CC865 in NmC (9/24; 38%). Peni was detected in 16% (42/262) of isolates, and was due to the presence of a penA mosaic, with the majority harboring penA7, penA9 or penA14.
CONCLUSIONS: IMD lineages circulating in South Africa were consistent with those circulating prior to 2008, however peni was higher than previously reported, and occurred in a variety of lineages.

OBJECTIVE: To identify recent trends in invasive meningococcal diseases (IMD) in Quebec, Canada, with a focus on MenY cases and MenY strains.
METHODS: IMD cases and MenY strains from January 1, 2015 to August 11, 2023 were analyzed for clonal analysis and prediction of susceptibility to MenB vaccines. MenY strains of ST-23 CC from Quebec were analyzed with global MenY strains by core-genomic multi-locus sequence typing (cg-MLST).
RESULTS: Since 2015 the serogroup distribution of IMD in Quebec has shifted from predominantly MenB to mainly MenY, with most (80.9 %) of the latter belonging to ST-23 CC. The median age of MenY cases due to ST-23 CC were statistically younger than MenY cases due to non-ST-23 CC. MenY of ST-23 CC showed genetic diversity and the major genetic cluster were similar to the Swedish Y1 strain. The increase in invasive MenY disease in Quebec was due to a sub-clade of Lineage 23.1 which caused an elevated proportion of severe disease in young adults.
CONCLUSIONS: The increase in invasive MenY disease in Quebec, Canada was driven by the expansion of a sub-clade of Lineage 23.1 in young adults. Currently available quadrivalent A,C,W,Y-conjugate meningococcal vaccines were predicted to provide protection against these strains.