Outbreak Of Meningococcal Disease Research Articles

A National Advisory Committee on Immunization (NACI) update on invasive meningococcal disease (IMD) epidemiology and program-relevant considerations for preventing IMD in individuals at high risk of exposure.

Following recent outbreaks of invasive meningococcal disease (IMD) in Canada and updates to provincial vaccination guidelines, the National Advisory Committee on Immunization (NACI) conducted a targeted review of evidence with a focus on immunization of adolescents and young adults. NACI reviewed national and international immunization recommendations for populations at high-risk of IMD, national IMD epidemiology and program-relevant considerations. Given the varied IMD epidemiology, NACI determined that recommending a pan-Canadian targeted program is currently challenging and that regional programs may be better suited to prevent IMD in population groups considered to be at high-risk of exposure. Further data is needed to ascertain contemporary risk factors for IMD (including activities and settings associated with bacterial acquisition, carriage and transmission) and estimate the true cost of meningococcal vaccine-preventable infections in Canada. To support provinces and territories in their decision-making, an outline of program-relevant elements for provincial and territorial consideration is provided.

Invasive Meningococcal Disease Among People Experiencing Homelessness-United States, 2016-2019.

Recently, several invasive meningococcal disease (IMD) outbreaks caused by Neisseria meningitidis have occurred among people experiencing homelessness (PEH). However, overall IMD risk among PEH is not well described. We compared incidence and characteristics of IMD among PEH and persons not known to be experiencing homelessness (non-PEH) in the United States. We analyzed 2016-2019 IMD data from the National Notifiable Diseases Surveillance System and enhanced meningococcal disease surveillance. Incidence was calculated using US census data and point-in-time counts from the US Department of Housing and Urban Development. Of cases from states participating in enhanced surveillance during 2016-2019 (n = 1409), 45 cases (3.2%) occurred among PEH. Annual incidence was higher among PEH (2.12 cases/100 000) than non-PEH (0.11 cases/100 000; relative risk, 19.8; 95% confidence interval [CI], 14.8-26.7). Excluding outbreak-associated cases (PEH n = 18, 40%; non-PEH n = 98, 7.2%), incidence among PEH remained elevated compared to incidence in non-PEH (relative risk, 12.8; 95% CI, 8.8-18.8). Serogroup C was identified in 68.2% of PEH cases compared to 26.4% in non-PEH (P < .0001). PEH are at increased risk for IMD. Further assessment is needed to determine the feasibility and potential impact of meningococcal vaccination for PEH in the United States.

Reactive vaccination as control strategy for an outbreak of invasive meningococcal disease caused by Neisseria meningitidis C:P1.5-1,10-8:F3-6:ST-11(cc11), Bergamo province, Italy, December 2019 to January 2020

In Italy, serogroup C meningococci of the clonal complex cc11 (MenC/cc11) have caused several outbreaks of invasive meningococcal disease (IMD) during the past 20 years. Between December 2019 and January 2020, an outbreak of six cases of IMD infected with MenC/cc11 was identified in a limited area in the northern part of Italy. All cases presented a severe clinical picture, and two of them were fatal. This report is focused on the microbiological and molecular analysis of meningococcal isolates with the aim to reconstruct the chain of transmission. It further presents the vaccination strategy adopted to control the outbreak. The phylogenetic evaluation demonstrated the close genetic proximity between the strain involved in this outbreak and a strain responsible for a larger epidemic that had occurred in 2015 and 2016 in the Tuscany Region. The rapid identification and characterisation of IMD cases and an extensive vaccination campaign contributed to the successful control of this outbreak caused by a hyperinvasive meningococcal strain.

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

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

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

BackgroundFrom 2015 to 2018, the Netherlands faced an outbreak of invasive meningococcal disease (IMD) caused by serogroup W. To counter the rise in infections, the government introduced a catch-up menACWY vaccination campaign for teenagers in 2018 and 2019. The outbreak situation induced substantial media attention and a run on menACWY vaccines outside the vaccination campaign. This study aimed to gain insights into the dynamics of public perceptions of and responses to the outbreak and the menACWY vaccination, and into the media coverage about the outbreak.MethodsThree repeated surveys (N = 1110) between 2017 and 2019 were sent to parents of teenagers invited for a menACWY catch-up vaccination, other parents, and individuals with no under-age children. These surveys assessed IMD risk perceptions, attitudes towards the menACWY vaccination, trust in involved institutions, and willingness to vaccinate with the menACWY vaccine. Changes in the public perceptions and responses were studied with linear multilevel regression analyses. In addition, 103 national newspaper articles from the period 2017–2019 were thematically coded with themes about IMD and the menACWY vaccination.ResultsThe survey results showed clear increases in perceived IMD severity, positive attitude towards the menACWY vaccination, and willingness to vaccinate over time. Perceived IMD vulnerability remained low across all three waves, and trust in involved institutions increased slightly. Differences between the survey groups were limited. The newspaper articles discussed the rise in infections extensively, the disease symptoms, and the possible fatal outcome of IMD. In addition, while many articles discussed the menACWY vaccine shortage, few discussed the safety or effectiveness of the vaccine.ConclusionThe real-time insights into the interrelated dynamics of public perceptions, responses, and media coverage provide an integrated portrait of the social developments during this outbreak. The focus on IMD severity and the absence of doubt in the public discussion about vaccine safety may have played an important role in the societal response to this outbreak and the recommended vaccine.

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.

Control of serogroup W meningococcal disease outbreaks: the promise of adolescent vaccination

Meningococcal disease is a serious bacterial infection caused by Neisseria meningitidis, usually presenting as meningitis, bacteraemia, or both. Even with appropriate treatment, the case fatality rate is approximately 10–15%, and 10–20% of survivors have long-term sequelae.1 N meningitidis colonises the oropharynx and is spread through the respiratory secretions of patients with meningococcal disease or asymptomatic carriers. In many regions, including Europe, adolescents and young adults have the highest carriage rates and are thus considered to be the primary source of transmission to other age groups.

Factor H binding protein (fHbp)-mediated differential complement resistance of a serogroup C Neisseria meningitidis isolate from cerebrospinal fluid of a patient with invasive meningococcal disease.

During an outbreak of invasive meningococcal disease (IMD) at the University of Southampton, UK, in 1997, two Neisseria meningitidis serogroup C isolates were retrieved from a student (‘Case’), who died of IMD, and a close contact (‘Carrier’) who, after mouth-to-mouth resuscitation on the deceased, did not contract the disease. Genomic comparison of the isolates demonstrated extensive nucleotide sequence identity, with differences identified in eight genes. Here, comparative proteomics was used to measure differential protein expression between the isolates and investigate whether the differences contributed to the clinical outcomes. A total of six proteins were differentially expressed: four proteins (methylcitrate synthase, PrpC; hypothetical integral membrane protein, Imp; fructose-1,6-bisphosphate aldolase, Fba; aldehyde dehydrogenase A, AldA) were upregulated in the Case isolate, while one protein (Type IV pilus-associated protein, PilC2) was downregulated. Peptides for factor H binding protein (fHbp), a major virulence factor and antigenic protein, were only detected in the Case, with a single base deletion (ΔT366) in the Carrier fHbp causing lack of its expression. Expression of fHbp resulted in an increased resistance of the Case isolate to complement-mediated killing in serum. Complementation of fHbp expression in the Carrier increased its serum resistance by approximately 8-fold. Moreover, a higher serum bactericidal antibody titre was seen for the Case isolate when using sera from mice immunized with Bexsero (GlaxoSmithKline), a vaccine containing fHbp as an antigenic component. This study highlights the role of fHbp in the differential complement resistance of the Case and the Carrier isolates. Expression of fHbp in the Case resulted in its increased survival in serum, possibly leading to active proliferation of the bacteria in blood and death of the student through IMD. Moreover, enhanced killing of the Case isolate by sera raised against an fHbp-containing vaccine, Bexsero, underlines the role and importance of fHbp in infection and immunity.

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

BackgroundTo counter the rise in invasive meningococcal disease (IMD) serogroup W, the Netherlands introduced a menACWY catch-up vaccination campaign for teenagers in 2018 and 2019. Teenagers and parents who have questions or who seek advice from a professional about vaccinations are likely to consult a youth healthcare professional or their general practitioner. This study aimed to appraise the ability of these healthcare professionals to meet the information needs of teenagers and their parents at the start of the vaccination campaign.MethodsWith online surveys, we assessed information needs in teenagers (N = 1603) and parents (N = 1784) concerning IMD and the menACWY vaccination, and in healthcare professionals (N = 520) in their communication with teenagers and parents. We additionally studied healthcare professionals’ expectations of the information needs of teenagers and parents.ResultsWe identified several information needs about IMD and the menACWY vaccination in teenagers, parents and healthcare professionals. Some important commonalities in the information needs in these three groups were found, with regard to the topics IMD prevention, vaccine effectiveness and vaccine protection duration. Healthcare professionals’ expectations of the information needs of teenagers and parents were quite accurate but some important discrepancies were found.ConclusionOur results suggest that healthcare professionals might not have been optimally equipped or prepared for questions from teenagers and their parents at the beginning of the vaccination campaign. We recommend public health institutes to timely assess and meet information needs about new vaccines in healthcare professionals to optimally equip them for consultations.

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).Plain Language Summary

Evaluation of Critical Quality Attributes of a Pentavalent (A, C, Y, W, X) Meningococcal Conjugate Vaccine for Global Use.

Towards achieving the goal of eliminating epidemic outbreaks of meningococcal disease in the African meningitis belt, a pentavalent glycoconjugate vaccine (NmCV-5) has been developed to protect against Neisseria meningitidis serogroups A, C, Y, W and X. MenA and X polysaccharides are conjugated to tetanus toxoid (TT) while MenC, Y and W polysaccharides are conjugated to recombinant cross reactive material 197 (rCRM197), a non-toxic genetic variant of diphtheria toxin. This study describes quality control testing performed by the manufacturer, Serum Institute of India Private Limited (SIIPL), and the independent control laboratory of the U.K. (NIBSC) on seven clinical lots of the vaccine to ensure its potency, purity, safety and consistency of its manufacturing. In addition to monitoring upstream-manufactured components, samples of drug substance, final drug product and stability samples were evaluated. This paper focuses on the comparison of the vaccine’s critical quality attributes and reviews key indicators of its stability and immunogenicity. Comparable results were obtained by the two laboratories demonstrating sufficient levels of polysaccharide O-acetylation, consistency in size of the bulk conjugate molecules, integrity of the conjugated saccharides in the drug substance and drug product, and acceptable endotoxin content in the final drug product. The freeze-dried vaccine in 5-dose vials was stable based on molecular sizing and free saccharide assays. Lot-to-lot manufacturing consistency was also demonstrated in preclinical studies for polysaccharide-specific IgG and complement-dependent serum bactericidal activity for each serogroup. This study demonstrates the high quality and stability of NmCV-5, which is now undergoing Phase 3 clinical trials in Africa and India.

Meningococcal Serogroup ACWYX Conjugate Vaccine in Malian Toddlers

BackgroundNeisseria meningitidis serogroups A, B, C, W, X, and Y cause outbreaks of meningococcal disease. Quadrivalent conjugate vaccines targeting the A, C, W, and Y serogroups are available. A pentavalent vaccine that also includes serogroup X (NmCV-5) is under development.MethodsWe conducted a phase 2, observer-blinded, randomized, controlled trial involving Malian children 12 to 16 months of age. Participants were assigned in a 2:2:1 ratio to receive nonadjuvanted NmCV-5, alum-adjuvanted NmCV-5, or the quadrivalent vaccine MenACWY-D, administered intramuscularly in two doses 12 weeks apart. Participants were followed for safety for 169 days. Immunogenicity was assessed with an assay for serum bactericidal antibody (SBA) with rabbit complement on days 0, 28, 84, and 112.ResultsA total of 376 participants underwent randomization, with 150 assigned to each NmCV-5 group and 76 to the MenACWY-D group; 362 participants received both doses of vaccine. A total of 1% of the participants in the nonadjuvanted NmCV-5 group, 1% of those in the adjuvanted NmCV-5 group, and 4% of those in the MenACWY-D group reported local solicited adverse events; 6%, 5%, and 7% of the participants, respectively, reported systemic solicited adverse events. An SBA titer of at least 128 was seen in 91 to 100% (for all five serotypes) of the participants in the NmCV-5 groups and in 36 to 99% (excluding serogroup X) of those in the MenACWY-D group at day 84 (before the second dose); the same threshold was met in 99 to 100% (for all five serotypes) of the participants in the NmCV-5 groups and in 92 to 100% (excluding serogroup X) of those in the MenACWY-D group at day 112. Immune responses to the nonadjuvanted and adjuvanted NmCV-5 formulations were similar.ConclusionsNo safety concerns were identified with two doses of NmCV-5. A single dose of NmCV-5 elicited immune responses that were similar to those observed with two doses of MenACWY-D. Adjuvanted NmCV-5 provided no discernible benefit over nonadjuvanted NmCV-5. (Funded by the U.K. Foreign, Commonwealth, and Development Office; ClinicalTrials.gov number, NCT03295318.)

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

ABSTRACTCarriage 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.

Serogroup B invasive meningococcal disease (IMD) outbreak at a Japanese high school dormitory: An outbreak investigation report from the first IMD outbreak in decades

PurposeThe first outbreak of invasive meningococcal disease (IMD) in decades occurred in a high school dormitory in 2011. This report aims to describe the results of the IMD outbreak investigation and to discuss current issues of IMD in Japan. MethodsWe conducted an epidemiological and microbiological investigation against the IMD outbreak of serogroup B among students and staff in a high school dormitory. Information on patients was collected to analyze risk factors for IMD. Control measures and public health actions were summarized. ResultsThree cases of meningitis and two cases of bacteremia were identified. Freshmen (15–16 years old) living in the dormitory with preceding cough were high-risk populations in this outbreak. Pulsed-field gel electrophoresis, multilocus sequence typing, and porA gene sequencing results revealed that all isolates were closely related to each other and had deep similarities to the domestic circulating meningococcal strain. The outbreak was terminated after promptly implementing control measures. Based on the results of our investigation, from April 2013, national infectious disease surveillance started to target meningococcal bacteremia as part of IMD, in addition to meningococcal meningitis, which was newly designated as a category II school infectious disease under the School Health and Safety Act. ConclusionsThis outbreak has enhanced public health measures against IMD in Japan. The development of national guidelines for appropriate public health interventions on the IMD outbreak response including chemoprophylaxis is still needed.

Meningococcal carriage among Hajj pilgrims, risk factors for carriage and records of vaccination: a study of pilgrims to Mecca.

ObjectiveThe Saudi government requires that all pilgrims receive a quadrivalent meningococcal vaccine at least 10 days before the Hajj. We conducted a study to determine the uptake of meningococcal vaccine and antibiotic use. We also investigated risk factors of meningococcal carriage and carriage of Neisseria meningitidis pathogenic serogroups A, C, W and Y.MethodsA cross‐sectional oropharyngeal carriage survey was conducted in 2973 Hajj pilgrims in September 2017. A real‐time polymerase chain reaction (rt‐PCR) assay was used to identify N. meningitidis from the oropharyngeal swabs. A questionnaire investigated potential risk factors for carriage of N. meningitidis.ResultsTwo thousand two hundred forty nine oropharyngeal swabs were obtained. The overall prevalence of carriage of N. meningitidis was 4.6% (95% CI: 3.4%–6%). Carriage of pathogenic serogroups was not associated significantly with any of the meningococcal risk factors evaluated. 77% of pilgrims were vaccinated but 22.58 % said they were carrying unofficial vaccination cards.ConclusionCarriage of serogroups A, C, W and Y was not significantly associated with any of the risk factors investigated. Almost a quarter of pilgrims were unlikely to have been vaccinated, highlighting a need to strengthen compliance with the current policy of vaccination to prevent meningococcal disease outbreaks during and after the Hajj.

Carriage Rate and Characteristics of Neisseria meningitidis among Dormitory Students.

In Japan, several meningococcal disease outbreaks have recently been reported among adolescent dormitory residents of schools. However, little is known about meningococcal carriage dynamics in healthy individuals. The purpose of this study was to investigate the carriage rate over time and characteristics of Neisseria meningitidis strains among dormitory students. The survey was conducted twice between November 2018 and January 2019 for first- to third-year students (N = 376) in a medical school dormitory. The two surveys yielded carriage rates of 0.4% (one positive among 257 students) and 2.1% (two positives among 97 students, including 90 re-participants). No transmission or persistence of a specific strain was observed during the two months. A limited number of students had a history of potential risk behaviors for carriage, such as smoking (3.0% [6/202] aged ≥20 years and 5.2% [4/77] aged ≥20 years, respectively) and attending parties more than once a week (4.3% [11/257] and 2.1% [2/97], respectively). Two isolates were unencapsulated, consistent with asymptomatic participants.

1429. Meningococcal Disease Outbreak in a Refugee Reception Identification Center in Greece and Administration of Mass Antibiotic Prophylaxis

BackgroundAn increased likelihood of transmission of communicable diseases such as invasive meningococcal disease (IMD) exists in refugee camps. Herein, we describe an outbreak investigation of 5 IMD cases among immigrants in Greece.MethodsEpidemiological, clinical and laboratory data (culture and molecular identification) as well as the public health management concerning an outbreak of meningococcal disease in a refugee Reception Identification Center (RIC), are described.ResultsDuring the period 17th January - 17th February 2020, five cases of IMD in refugees were reported to the National Public Health Organization (NPHO). Four cases were from Afghanistan and resided in the RIC of Lesvos Island; two females aged 2 yo and 21 yo and two males 13 yo and 6 yo. The fifth case, a 4 month old male of Syrian nationality, exhibited symptoms after moving to an inland accommodation center (AC) from Lesvos RIC, on December 2019. Four of the cases presented with meningitis and septicaemia. All cases recovered and had no common exposure other than shared geographic space. Neisseria meningitidis was identified by molecular typing (mPCR, PorA, MLST, WGS) in all cases at the National Meningitis Reference Laboratory; 3/5 cases were identified as MenB, porA 7-2,4, and ST-3129 (new clone) while 2/5 (21 yo female, 13 yo male) as MenY, porA: 5.2, ST-22cc. To prevent secondary cases, antimicrobial chemoprophylaxis via Directly Observed Therapy (DOT) was administered to 4.024 Afgan close contacts (26.7% of the total Afgan population). MenACWY and MenB vaccination was recommended in response to outbreak among persons aged < 20 years old. No new IMD case occurred in the RIC during a follow-up period of 4 months.ConclusionThe detection of a new clone in Greece of Chinese and Taiwanese origin through migrants, further underlines the need of enhanced surveillance for early detection, molecular typing, immediate intervention with antibiotic prophylaxis and/or supplemental vaccination in order to prevent IMD in refugee camps.Disclosures All Authors: No reported disclosures

Rapid Transmission of a Hyper-Virulent Meningococcal Clone Due to High Effective Contact Numbers and Super Spreaders.

Rapid transmission, a critical contributory factor in outbreaks of invasive meningococcal disease, requires naïve populations of sufficient size and intermingling. We examined genomic variability and transmission dynamics in a student population subject to an 11-fold increase in carriage of a hypervirulent Neisseria meningitidis serogroup W ST-11 clone. Phylogenetic clusters, mutation and recombination rates were derived by bioinformatic analyses of whole-genome sequencing data. Transmission dynamics were determined by combining observed carriage rates, cluster sizes and distributions with simple SIS models. Between 9 and 15 genetically-distinct clusters were detected and associated with seven residential halls. Clusters had low mutation accumulation rates and infrequent recombination events. Modeling indicated that effective contacts decreased from 10 to 2 per day between the start and mid-point of the university term. Transmission rates fluctuated between 1 and 4% while the R(t) for carriage decreased from an initial rate of 47 to 1. Decreases in transmission values correlated with a rise in vaccine-induced immunity. Observed carriage dynamics could be mimicked by populations containing 20% of super spreaders with 2.3-fold higher effective contact rates. We conclude that spread of this hypervirulent ST-11 meningococcal clone depends on the levels of effective contacts and immunity rather than genomic variability. Additionally, we propose that super-spreaders enhance meningococcal transmission and that a 70% MenACWY immunization level is sufficient to retard, but not fully prevent, meningococcal spread in close-contact populations.

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

SummaryThis 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.

Lesson learned from an outbreak of invasive meningococcal disease: how HTA could have provided an evidence-based approach for public health response

Abstract During 2015-2016 an outbreak of invasive meningococcal disease due to Neisseria meningitidis serogroup C ST-11 (cc11) occurred in Tuscany, a Region in Central Italy. Sixty-two cases with 13 deaths (13%) were recorded. Regional Authorities responded through a mass immunization campaign targeting all the age groups by offering free of charge a single dose of the tetravalent (ACWY) meningococcal conjugate vaccine or monovalent meningococcal C conjugate (MCC) vaccine. Nevertheless, the response was fragmented and the campaign did not reach the risk-population groups (i.e. men who have sex with men), that were identified only when a Regional outbreak investigation was implemented. Also linkage between cases (i.e. attending the same gay-venue) were identified at a second stage, not allowing prompt max-prophylaxis interventions. In such a situation, an evidence-based approach as Health Technology Assessment, could have informed public health emergency preparedness and response planning processes, i.e. by identifying through early warning alert systems similar ongoing clusters in Europe among specific population-groups and consequently better targeting the immunization campaign. The objective of this presentation is to explore through a practical example how HTA could provide an evidence-based approach for public health response during a real outbreak underlining lesson learned.