Impact of MenAfriVac in nine countries of the African meningitis belt, 2010-15: an analysis of surveillance data

The burden of common neurological disorders in Asia: insights from the Global Burden of Disease Study (1990-2021)

BACKGROUND

Neurological disorders represent a significant global health issue, leading to severe cognitive impairments and being a major cause of premature mortality and disability. This study aims to utilize data from the Global Burden of Disease (GBD) research website to assess the burden of neurological disorders in the Asian region and its individual countries and territory from 1990 to 2021, with the goal of providing reference for global efforts and decision-making in the prevention, treatment, and management of neurological disorders.

METHODS

Based on the Global Burden of Disease data, this study assessed the incidence, prevalence, mortality, and disability-adjusted life years (DALYs) of 13 neurological disorders in the Asian region from 1990 to 2021. The epidemiological characteristics of neurological disorders across these Asian regions were analyzed. Joinpoint regression analysis was employed to assess the temporal patterns of the burden of neurological disorders, and the average annual percent change (AAPC) was calculated to determine the overall trend throughout the study period.

RESULTS

In 2021, stroke, migraine, and Alzheimer's disease and other dementias emerged as the primary contributors to neurological burden in Asia, with stroke accounting for 112.87 million disability-adjusted life years (DALYs), followed by migraine (25.4 million) and Alzheimer's disease and other dementias (20.0 million). Stroke was also the leading cause of neurological mortality (5.03 million deaths), trailed by Alzheimer's disease and other dementias (1.0 million). Stroke, migraine, and tension-type headache had the highest prevalence rates among neurological disorders, with 57.3 million, 683.5 million, and 1130.2 million. Temporal trends from 1990 to 2021 revealed a significant decline in age-standardized DALY rates for stroke (estimated annual percentage change [EAPC]: - 1.65%), though absolute DALYs increased (EAPC: 0.06%). In contrast, Alzheimer's disease and other dementias exhibited rising age-standardized (EAPC: 0.14%) and absolute DALYs (EAPC: 2.8%), while infectious neurological diseases (e.g., meningitis, tetanus) demonstrated marked reductions in burden. Sex-specific disparities were evident, with males experiencing a higher total DALY burden (84.8 million vs. 77.05 million), driven by stroke and Parkinson's disease, whereas Alzheimer's disease and other dementias and migraine disproportionately affected females. Geographically, stroke dominated Southeast Asia (67.6% of regional DALYs), while migraine contributed most substantially to West Asia (16%). Nationally, stroke ranked as the leading cause of neurological DALYs in most Asian countries, contrasting with migraine in Israel, Kuwait, Qatar, and the United Arab Emirates. Longitudinal analyses highlighted accelerated declines in stroke DALYs post- 2004 but escalating burdens for Alzheimer's disease and other dementias after 2019, reflecting divergent epidemiological trajectories.

CONCLUSIONS

In 2021, the burden of neurological disorders in Asia remained substantial, with stroke, migraine, and Alzheimer's disease and other dementias being the top three contributors to DALYs. The study also revealed significant differences in the burden of neurological disorders across various subregions and countries in Asia, highlighting the need for enhanced international collaboration, sharing of best practices, provision of technical support, and optimization of healthcare resource allocation.

Safety and immunogenicity of a pentavalent meningococcal conjugate vaccine versus a quadrivalent meningococcal conjugate vaccine in adults in India: an observer-blind, randomised, active-controlled, phase 2/3 study

BACKGROUND

Meningococcal disease remains an important public health problem globally. We assessed the non-inferiority and the lot-to-lot consistency of a pentavalent meningococcal ACYWX conjugate vaccine (NmCV-5; Serum Institute of India, Pune, India) versus a quadrivalent meningococcal ACWY conjugate vaccine (MenACWY-D) in healthy adults.

METHODS

In this observer-blind, randomised, active-controlled, phase 2/3 study, healthy adults aged 18-85 years were recruited from nine hospitals across seven cities in India. Participants were grouped by age (age 18-29, 30-60, and 61-85 years), and within each age group they were randomly assigned (3:1) to receive either NmCV-5 or MenACWY-D (Sanofi Pasteur). In the age 18-29 years group, participants were additionally randomly assigned (1:1:1:1) to either lot A, lot B, or lot C of NmCV-5 or MenACWY-D. Block randomisation was used (block sizes of 4, 8, and 12). Study participants and study personnel were masked to treatment assignment. Participants received either a 0·5 mL dose of NmCV-5, containing 5 μg each of conjugated A, C, W, Y, and X polysaccharides, or 0·5 mL MenACWY-D, containing 4 μg of each of conjugated A, C, W, and Y polysaccharides. Vaccinations were administered intramuscularly in the deltoid muscle. The primary outcomes were seroresponse (non-inferiority margin of -10%) and geometric mean titres (GMTs; non-inferiority margin of 0·5) in all participants, and lot-to-lot consistency of NmCV-5 (in participants aged 18-29 years; consistency was shown if the geometric mean ratio [GMR] 95% CIs were within the limit interval of 0·5 to 2). For non-inferiority, serogroup X immune response in the NmCV-5 group was compared with the lowest immune response among serogroups A, C, W, and Y in the MenACWY-D group. Immunogenicity was assessed with a serum bactericidal activity assay that used baby rabbit serum as the complement (rSBA) on days 1 and 29 in the modified per-protocol population (including all participants who were randomly assigned, received vaccine, had a post-vaccination rSBA measurement up to 121 days after vaccination, and no major protocol violations). Solicited events were collected for 7 days and serious adverse events were collected for 180 days, and assessed in the safety population (all participants who received vaccination). This study is registered with ClinicalTrials.gov, NCT04358731, and CTRI, CTRI/2019/12/022436, and is now complete.

FINDINGS

Between Dec 27, 2019, and Sept 19, 2020, 1712 individuals were screened, of whom 1640 were randomly assigned and received NmCV-5 (n=1233) or MenACWY-D (n=407; mean age 26·4 years [SD 12·2], 551 [33·6%] of 1640 were female, and 1089 [66·4%] were male). 1441 participants were aged 18-29 years (362 received lot A, 360 received lot B, and 361 received lot C of NmCV-5 and 357 received MenACWY-D, with one participant mis-randomised by age group and excluded from lot-to-lot consistency analysis). Non-inferiority of NmCV-5 against MenACWY-D was met in terms of seroresponse rates and GMT ratios for all five serogroups. The seroresponse rates were 84·3% (97·5% CI 81·7 to 86·7; serogroup A) or higher in the NmCV-5 group and 54·5% (48·5 to 60·3; serogroup A) or higher in the MenACWY-D group, with the difference in the seroresponse rate between vaccine groups ranging from 0·2 (97·5% CI -2·2 to 2·6) for serogroup W to 29·8 (24·4 to 35·2) for serogroup A. GMTs on day 29 were 7016·9 (97·5% CI 6475·7 to 7603·4; serogroup Y) or higher in the NmCV-5 group and 3646·8 (3188·2 to 4171·5; serogroup Y) or higher in the MenACWY-D group, with GMT ratios between vaccine groups for serogroups A, C, Y, and W ranging from 1·9 (97·5% CI 1·5-2·3) for serogroup W to 2·5 (2·2-2·8) for serogroup A. NmCV-5 induced robust immune responses against serogroup X. Lot-to-lot consistency of NmCV-5 was found for all five serogroups, with 95% CIs for the GMT ratio for each pair of lots being between 0·5 and 2: the lowest lower bound and the highest upper bound of the 95% CI for the GMR between NmCV-5 lot A and lot B were 0·6 and 1·4, between lot A and lot C were 0·7 and 1·6, and between lot B and lot C were 0·8 and 1·6, respectively, for any of the five serogroups. At least one solicited adverse event was reported by 527 (42·7%) of 1233 participants in the NmCV-5 group and 142 (34·9%) of 407 in the MenACWY-D group. No serious adverse events occurred that were determined to be causally related to vaccination.

INTERPRETATION

NmCV-5 was non-inferior to MenACWY-D in terms of seroresponse and GMTs, was safe, and demonstrated lot-to-lot consistency. NmCV-5 is prequalified by WHO and was rolled out in the African meningitis belt in April, 2024.

FUNDING

Serum Institute of India.

Safety and immunogenicity of a pentavalent meningococcal conjugate vaccine targeting serogroups A, C, W, Y, and X when co-administered with routine childhood vaccines at ages 9 months and 15 months in Mali: a single-centre, double-blind, randomised, controlled, phase 3, non-inferiority trial

BACKGROUND

Invasive meningococcal disease is a devastating public health problem for the African meningitis belt. We assessed the safety and immunogenicity of a pentavalent meningococcal conjugate vaccine targeting serogroups A, C, Y, W, and X (NmCV-5) relative to a licensed, quadrivalent meningococcal conjugate vaccine (MenACWY-TT) when co-administered with routine childhood vaccines at ages 9 months and 15 months.

METHODS

In this single-centre, double-blind, randomised, controlled, phase 3, non-inferiority trial, children aged 9-11 months who had completed their local infant Expanded Program on Immunization (EPI) vaccines were recruited at the Centre pour le Développement des Vaccins in Bamako, Mali. Participants were randomly assigned (1:1·2) at their 9-month EPI visits to receive a meningococcal vaccine at either their 9-month or 15-month EPI vaccination visits. At each participant's designated EPI visit, they were randomly assigned a second time (2:1) to receive either NmCV-5 or MenACWY-TT. Study vaccines and designated EPI vaccines were prepared and administered by assigned unmasked study personnel. Parents or guardians, investigators, and all other trial staff were masked to meningococcal vaccine assignments. The meningococcal vaccines were co-administered with a measles and rubella vaccine (first dose) and a yellow fever vaccine at age 9 months or with a measles and rubella vaccine (second dose) at age 15 months. The primary endpoint, seroprotective response, was defined as a rabbit complement serum bactericidal antibody titre of 8 or higher, with the estimand, given as the difference in the proportions of participants for each of the five meningococcal serogroups who showed this response 28 days after vaccination, assessed in the per-protocol population. The prespecified non-inferiority margin was -10% for all five serogroups in both age groups. The non-inferiority of the NmCV-5 seroprotective response to serogroup X was evaluated in comparison with the lowest seroprotective response for MenACWY-TT among serogroups A, C, W, or Y. Safety was a secondary endpoint, assessed over 6 months in a modified intention-to-treat population that included all participants who received a randomly assigned meningococcal vaccine. This trial is registered with ClinicalTrials.gov, NCT05093829.

FINDINGS

Between March 24 and Aug 15, 2022, 1325 participants were enrolled and randomly assigned to receive a meningococcal vaccine at either age 9 months (n=602) or age 15 months (n=723). Meningococcal vaccines were administered to 600 of the 602 participants assigned to the 9-month vaccination group during that same period. Between Sept 27, 2022, and Feb 6, 2023, 600 participants received meningococcal vaccines at their 15-month visits. In both groups, 400 participants received NmCV-5 and 200 participants received MenACWY-TT. The per-protocol population assessed in the non-inferiority analysis included 564 participants vaccinated at age 9 months (373 who received NmCV-5 and 191 who received MenACWY-TT) and 549 participants vaccinated at age 15 months (367 who received NmCV-5 and 182 who received MenACWY-TT). Among the participants in the per-protocol population who received NmCV-5 at age 9 months, the difference in seroprotection prevalence for NmCV-5 relative to MenACWY-TT was 0·0% (95% CI -1·0 to 2·0) for serogroup A, -0·5% (-2·3 to 1·9) for serogroup C, -3·0% (-6·3 to 0·8) for serogroup W, and -3·0% (-5·4 to -0·4) for serogroup Y. For serogroup X, non-inferiority was assessed relative to seroprotection for serogroup W in participants who received MenACWY-TT, with a difference of 2·3% (95% CI 0·3 to 4·7). The difference in the prevalence of seroprotection among the participants who received NmCV-5 at age 15 months relative to participants who received MenACWY-TT at age 15 months was 0·8% (95% CI -0·6 to 3·7) for serogroup A, -0·8% (-3·3 to 2·5) for serogroup C, 0·3% (-1·8 to 3·5) for serogroup W, and 1·4% (-0·6 to 4·8) for serogroup Y. For serogroup X, non-inferiority was assessed in relation to seroprotection for serogroup Y in participants who received MenACWY-TT, with a difference of 1·9% (95% CI 0·0 to 4·4). NmCV-5 responses in both age groups were non-inferior to MenACWY-TT responses for all five serogroups. Six serious adverse events were recorded but none were deemed related to vaccination.

INTERPRETATION

When compared with a licensed, quadrivalent meningococcal conjugate vaccine, and given alongside other routine vaccines, a single dose of NmCV-5 was safe and elicited a non-inferior immune response in infants aged 9 months and young children aged 15 months.

FUNDING

US National Institutes of Health, UK Foreign, Commonwealth & Development Office, and Serum Institute of India.

Epidemiology, microbiology and antibiotic treatment of bacterial and fungal meningitis among very preterm infants in China: a cross-sectional study

OBJECTIVE

Neonatal meningitis significantly contributes to neonatal morbidity and mortality, yet large-scale epidemiological data in developing countries, particularly among very preterm infants (VPIs), remain sparse. This study aimed to describe the epidemiology of meningitis among VPIs in China.

DESIGN

Cross-sectional study using the Chinese Neonatal Network database from 2019 to 2021.

SETTING

79 tertiary neonatal intensive care units in China.

PATIENTS

Infants with gestational age <32 weeks or birth weight <1500 g.

MAIN OUTCOME MEASURES

Incidence, pathogen distribution, antimicrobial use and outcomes of bacterial and fungal meningitis.

RESULTS

Of 31 915 VPIs admitted, 122 (0.38%) infants were diagnosed with culture-confirmed meningitis, with 14 (11.5%) being early-onset (≤6 days of age) and 108 (88.5%) being late-onset (>6 days of age). The overall in-hospital mortality was 18.0% (22/122). A total of 127 pathogens were identified, among which 63.8% (81/127) were Gram-negative bacteria, 24.4% (31/127) were Gram-positive bacteria and 11.8% (15/127) were fungi. In terms of empirical therapy (on the day of the first lumbar puncture), the most commonly used antibiotic was meropenem (54.9%, 67/122). For definitive therapy (on the sixth day following the first lumbar puncture, 86 cases with available antibiotic data), meropenem (60.3%, 35/58) and vancomycin (57.1%, 16/28) were the most used antibiotics for Gram-negative and Gram-positive bacterial meningitis, respectively. 44% of infants with Gram-positive bacterial meningitis and 52% with Gram-negative bacterial meningitis received antibiotics for more than 3 weeks.

CONCLUSION

0.38% of VPIs in Chinese neonatal intensive care units were diagnosed with meningitis, experiencing significant mortality and inappropriate antibiotic therapy. Gram-negative bacteria were the predominant pathogens, with fungi emerging as a significant cause.

Addressing the re-emergence and resurgence of vaccine-preventable diseases in Africa: A health equity perspective

Vaccination is one of the greatest public health achievements of the 20th century, with a tremendous impact in the prevention and control of diseases. However, the recent reemergence of vaccine-preventable diseases calls for a need to evaluate current vaccination practices and disparities in vaccination between high-income countries and low-and-middle-income countries. There are massive deficits in vaccine availability and coverage in resource-constrained settings. Therefore, this perspective seeks to highlight the reemergence of vaccine-preventable diseases in Africa within the lens of health equity and offer recommendations on how the continent should be prepared to deal with the myriad of its health systems challenges. Among the notable factors contributing to the reemergence, stand health inequities affecting vaccine availability and the dynamic vaccine hesitancy. Strengthening health systems and addressing health inequities could prove useful in halting the reemergence of vaccine-preventable diseases.

Spatiotemporal dynamics of the oropharyngeal microbiome in a cohort of Ivorian school children

The respiratory tract harbours microorganisms of the normal host microbiota which are also capable of causing invasive disease. Among these, Neisseria meningitidis a commensal bacterium of the oropharynx can cause meningitis, a disease with epidemic potential. The oral microbiome plays a crucial role in maintaining respiratory health. An imbalance in its composition is associated with increased risk of invasive disease. The main objective of this study was to evaluate changes in the spatio-temporal dynamics of the oropharyngeal microbiota considering meningococcal carriage in a cohort of 8-12-year-old school children within (Korhogo) and outside (Abidjan) of the meningitis belt of Côte d'Ivoire. A significant geographic difference in the oropharyngeal microbiome was identified between the two study sites in terms of bacterial abundance and diversity (p < 0.001), with greater diversity in children in Abidjan than in Korhogo. Meningococcal carriage was low in the cohort with eight Neisseria carriers identified in Korhogo (3.64%) including one Neisseria meningitidis (0.45%). No Neisseria were detected in Abidjan indicating geographical differences in carriage (p = 0.006). Negative correlations were also found between Neisseria abundance and humidity. Meningococcal carriage was very low during the study; however, Neisseria carriage differed between the two study areas, with a higher frequency in children in Korhogo. Analysis of the oropharyngeal microbiome showed significant differences between children followed in Abidjan and Korhogo with higher microbial diversity in Abidjan, which is generally associated with better health status. Significant correlations between Neisseria or other pathogens carriage and climatic variables (Temperature, Relative humidity, and Wind speed) were also demonstrated, indicating an important role of climate in the carriage of these bacteria; an important element to note in the current context of climate change.

Global Epidemiology of Meningococcal Disease-Causing Serogroups Before and After the COVID-19 Pandemic: A Narrative Review

Invasive meningococcal disease (IMD) is associated with high morbidity and mortality and predominantly caused by five Neisseria meningitidis serogroups (A/B/C/W/Y). Polysaccharide conjugate vaccines induce T-cell-dependent immune responses, are immunogenic in infants and adults, and reduce carriage, and vaccination of age groups associated with high-carriage can provide indirect protection in the unvaccinated (herd immunity). Successful vaccination programs must be tailored to local epidemiology, which varies geographically, temporally, and by age and serogroup. Serogroup A IMD once predominated globally, but has largely disappeared following mass vaccination programs. Serogroup B was a predominant cause of IMD in many global regions from 2010 to 2018, typically affecting younger age groups. Spread of serogroup C clonal complex-11 IMD in the 1990s prompted implementation of MenC vaccine programs in many countries, resulting in declines in prevalence. Serogroup C still caused > 20% of global IMD through the mid-2010s. Serogroup W became a significant contributor to global IMD after Hajj pilgrimage outbreaks in 2000; subsequent increases of endemic disease and outbreaks were reported pre-pandemic in many regions. Serogroup Y emerged in the 1990s as a significant cause of IMD throughout various regions and prevalence had increased or stabilized from 2010 to 2018. Serogroup X is uncommon outside the African meningitis belt, and its prevalence has declined since before the COVID-19 pandemic. Global IMD declines during the pandemic were followed by resurgences generally caused by serogroups that were prevalent pre-pandemic and affecting mainly unvaccinated age groups (particularly adolescents/young adults). Recent IMD epidemiology underscores the importance of vaccinating at-risk age groups against regionally prevalent serogroups; for example, the anti-serogroup X component of the recently prequalified MenACWXY vaccine is likely to provide limited protection outside the African meningitis belt. In other regions, comprehensive vaccination against MenB and MenACWY, which could be streamlined by the recently approved MenABCWY vaccine, seems more appropriate.

Analysis of immunogenicity and purification methods in conjugated polysaccharide vaccines: a new approach in fighting pathogenic bacteria

Carbohydrates are commonly found in conjunction with lipids or proteins, resulting in the formation of glycoconjugates such as glycoproteins, glycolipids, and proteoglycans. These glycoconjugates are essential in various biological activities, including inflammation, cell-cell recognition, bacterial infections, and immune response. Nonetheless, the isolation of naturally occurring glycoconjugates presents challenges due to their typically heterogeneous nature, resulting in variations between batches in structure and function, impeding a comprehensive understanding of their mechanisms of action. Consequently, there is a strong need for the efficient synthesis of artificial glycoconjugates with precisely described compositions and consistent biological properties. The chemical and enzymatic approaches discussed in this paper present numerous research opportunities to develop customised glycoconjugate vaccines.

The Bacterial Meningitis Epidemic in Banalia in the Democratic Republic of Congo in 2021

BACKGROUND

The Banalia health zone in the Democratic Republic of Congo reported a meningitis epidemic in 2021 that evolved outside the epidemic season. We assessed the effects of the meningitis epidemic response.

METHODS

The standard case definition was used to identify cases. Care was provided to 2651 in-patients, with 8% of them laboratory tested, and reactive vaccination was conducted. To assess the effects of reactive vaccination and treatment with ceftriaxone, a statistical analysis was performed.

RESULTS

Overall, 2662 suspected cases of meningitis with 205 deaths were reported. The highest number of cases occurred in the 30-39 years age group (927; 38.5%). Ceftriaxone contributed to preventing deaths with a case fatality rate that decreased from 70.4% before to 7.7% after ceftriaxone was introduced (p = 0.001). Neisseria meningitidis W was isolated, accounting for 47/57 (82%), of which 92% of the strains belonged to the clonal complex 11. Reactive vaccination of individuals in Banalia aged 1-19 years with a meningococcal multivalent conjugate (ACWY) vaccine (Menactra®) coverage of 104.6% resulted in an 82% decline in suspected meningitis cases (incidence rate ratio, 0.18; 95% confidence interval, 0.02-0.80; p = 0.041).

CONCLUSION

Despite late detection (two months) and reactive vaccination four months after crossing the epidemic threshold, interventions implemented in Banalia contributed to the control of the epidemic.

The important lessons lurking in the history of meningococcal epidemiology

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

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

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

METHODOLOGY

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

RESULTS

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

CONCLUSIONS

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

Meningococcal Disease in the Post-COVID-19 Era: A Time to Prepare

The global invasive meningococcal disease (IMD) landscape changed considerably during the COVID-19 pandemic, as evidenced by decreased incidence rates due to COVID-19 mitigation measures, such as limited social contact, physical distancing, mask wearing, and hand washing. Vaccination rates were also lower during the pandemic relative to pre-pandemic levels. Although policymakers may have shifted their focus away from IMD vaccination programs to COVID-19 vaccination programs, strong arguments support implementation and prioritization of IMD vaccination programs; IMD cases have increased in some countries and IMD rates may even have exceeded pre-pandemic levels. Additional concerns include increased susceptibility due to vaccination coverage gaps, increased incidence of other respiratory pathogens, immunity debt from lockdown restrictions, and increased IMD epidemiologic variability. The full range of benefits of widely available and effective meningococcal vaccines needs to be considered, especially in health technology assessments, where the broad benefits of these vaccines are neither accurately quantified nor captured in implementation policy decisions. Importantly, implementation of meningococcal vaccination programs in the current IMD climate also appeals to broader healthcare principles, including preparedness rather than reactive approaches, generally accepted benefit-risk approaches to vaccination, historical precedent, and the World Health Organization's goal of defeating meningitis by 2030. Countries should therefore act swiftly to bolster existing meningococcal vaccination strategies to provide broad coverage across age groups and serogroups given the recent increases in IMD incidence.

High-Frequency Changes in Pilin Glycosylation Patterns during Neisseria meningitidis Serogroup a Meningitis Outbreaks in the African Meningitis Belt

In the meningitis belt of sub-Saharan Africa, there are cyclic meningococcal epidemics that coincide with clonal waves of Neisseria meningitidis carriage and invasive disease. In the framework of longitudinal colonization and disease studies in Ghana and Burkina Faso, meningococcal isolates belonging to the closely related hypervirulent A:ST-5, A:ST-7, and A:ST-2859 clones have been collected from 1998 to 2011 during meningococcal outbreaks. A comparative whole-genome sequencing study with 100 of these isolates identified the pilin glycosylation (pgl) locus as one hot spot of recombination. Frequent exchange of pgl genes in N. meningitidis by lateral gene transfer results in differences in the glycosylation patterns of pilin and other cell surface glycoproteins. In this study, we looked at both recombination and phase variation of the pgl genes of these clinical isolates and analyzed the glycan structures resulting from different pgl alleles and their variable expression. Our results indicate that the basal O-linked sugar of the glycans expressed by these isolates is masked by various additional mono- or disaccharide structures whose expression is highly variable due to the phase-variable expression of pgl genes. We also observed a distinct glycoform in two isolates with pgl loci that were modified by recombination. These data suggest that variation in N. meningitidis protein glycosylation could be crucial for bacterial adaptation to evade herd immunity in semi-immune populations. Investigating pilin glycosylation in N. meningitidis can shed light on the mechanisms by which this pathogen evades the host immune response, and may help identify potential targets for novel therapies and vaccines.

Real-world impact and effectiveness of MenACWY-TT

In response to escalating cases of serogroup W (MenW) invasive meningococcal disease (IMD), multiple countries introduced quadrivalent conjugate MenACWY vaccines into their national immunization programs (NIPs). Here, we summarize the real-world impact and vaccine effectiveness (VE) data of MenACWY-TT from Chile, England, the Netherlands, and Australia. Incidence rate reductions (IRRs) and VE from baseline to post-NIP period were extracted from publications or calculated. After the administration of a single dose of MenACWY-TT, substantial IRRs of MenCWY were observed across the countries in vaccine-eligible age groups (83%-85%) and via indirect protection in non-vaccine-eligible age groups (45%-53%). The impact of MenACWY-TT was primarily driven by MenW IRRs, as seen in vaccine-eligible age groups (65%-92%) and non-vaccine-eligible age groups (41%-57%). VE against MenW was reported in vaccine-eligible toddlers (92%) in the Netherlands and in vaccine-eligible adolescents/young adults (94%) in England. These real-world data support the implementation and continued use of MenACWY-TT in NIPs.

Global, regional, and national burden of meningitis and its aetiologies, 1990-2019: a systematic analysis for the Global Burden of Disease Study 2019

BACKGROUND

Although meningitis is largely preventable, it still causes hundreds of thousands of deaths globally each year. WHO set ambitious goals to reduce meningitis cases by 2030, and assessing trends in the global meningitis burden can help track progress and identify gaps in achieving these goals. Using data from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we aimed to assess incident cases and deaths due to acute infectious meningitis by aetiology and age from 1990 to 2019, for 204 countries and territories.

METHODS

We modelled meningitis mortality using vital registration, verbal autopsy, sample-based vital registration, and mortality surveillance data. Meningitis morbidity was modelled with a Bayesian compartmental model, using data from the published literature identified by a systematic review, as well as surveillance data, inpatient hospital admissions, health insurance claims, and cause-specific meningitis mortality estimates. For aetiology estimation, data from multiple causes of death, vital registration, hospital discharge, microbial laboratory, and literature studies were analysed by use of a network analysis model to estimate the proportion of meningitis deaths and cases attributable to the following aetiologies: Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae, group B Streptococcus, Escherichia coli, Klebsiella pneumoniae, Listeria monocytogenes, Staphylococcus aureus, viruses, and a residual other pathogen category.

FINDINGS

In 2019, there were an estimated 236 000 deaths (95% uncertainty interval [UI] 204 000-277 000) and 2·51 million (2·11-2·99) incident cases due to meningitis globally. The burden was greatest in children younger than 5 years, with 112 000 deaths (87 400-145 000) and 1·28 million incident cases (0·947-1·71) in 2019. Age-standardised mortality rates decreased from 7·5 (6·6-8·4) per 100 000 population in 1990 to 3·3 (2·8-3·9) per 100 000 population in 2019. The highest proportion of total all-age meningitis deaths in 2019 was attributable to S pneumoniae (18·1% [17·1-19·2]), followed by N meningitidis (13·6% [12·7-14·4]) and K pneumoniae (12·2% [10·2-14·3]). Between 1990 and 2019, H influenzae showed the largest reduction in the number of deaths among children younger than 5 years (76·5% [69·5-81·8]), followed by N meningitidis (72·3% [64·4-78·5]) and viruses (58·2% [47·1-67·3]).

INTERPRETATION

Substantial progress has been made in reducing meningitis mortality over the past three decades. However, more meningitis-related deaths might be prevented by quickly scaling up immunisation and expanding access to health services. Further reduction in the global meningitis burden should be possible through low-cost multivalent vaccines, increased access to accurate and rapid diagnostic assays, enhanced surveillance, and early treatment.

FUNDING

Bill & Melinda Gates Foundation.

Meningococcal ACWYX Conjugate Vaccine in 2-to-29-Year-Olds in Mali and Gambia

BACKGROUND

An effective, affordable, multivalent meningococcal conjugate vaccine is needed to prevent epidemic meningitis in the African meningitis belt. Data on the safety and immunogenicity of NmCV-5, a pentavalent vaccine targeting the A, C, W, Y, and X serogroups, have been limited.

METHODS

We conducted a phase 3, noninferiority trial involving healthy 2-to-29-year-olds in Mali and Gambia. Participants were randomly assigned in a 2:1 ratio to receive a single intramuscular dose of NmCV-5 or the quadrivalent vaccine MenACWY-D. Immunogenicity was assessed at day 28. The noninferiority of NmCV-5 to MenACWY-D was assessed on the basis of the difference in the percentage of participants with a seroresponse (defined as prespecified changes in titer; margin, lower limit of the 96% confidence interval [CI] above -10 percentage points) or geometric mean titer (GMT) ratios (margin, lower limit of the 98.98% CI >0.5). Serogroup X responses in the NmCV-5 group were compared with the lowest response among the MenACWY-D serogroups. Safety was also assessed.

RESULTS

A total of 1800 participants received NmCV-5 or MenACWY-D. In the NmCV-5 group, the percentage of participants with a seroresponse ranged from 70.5% (95% CI, 67.8 to 73.2) for serogroup A to 98.5% (95% CI, 97.6 to 99.2) for serogroup W; the percentage with a serogroup X response was 97.2% (95% CI, 96.0 to 98.1). The overall difference between the two vaccines in seroresponse for the four shared serogroups ranged from 1.2 percentage points (96% CI, -0.3 to 3.1) for serogroup W to 20.5 percentage points (96% CI, 15.4 to 25.6) for serogroup A. The overall GMT ratios for the four shared serogroups ranged from 1.7 (98.98% CI, 1.5 to 1.9) for serogroup A to 2.8 (98.98% CI, 2.3 to 3.5) for serogroup C. The serogroup X component of the NmCV-5 vaccine generated seroresponses and GMTs that met the prespecified noninferiority criteria. The incidence of systemic adverse events was similar in the two groups (11.1% in the NmCV-5 group and 9.2% in the MenACWY-D group).

CONCLUSIONS

For all four serotypes in common with the MenACWY-D vaccine, the NmCV-5 vaccine elicited immune responses that were noninferior to those elicited by the MenACWY-D vaccine. NmCV-5 also elicited immune responses to serogroup X. No safety concerns were evident. (Funded by the U.K. Foreign, Commonwealth, and Development Office and others; ClinicalTrials.gov number, NCT03964012.).

Understanding barriers to vaccination against invasive meningococcal disease: a survey of the knowledge gap and potential solutions

INTRODUCTION

Invasive meningococcal disease (IMD) is a leading cause of life-threatening bacterial meningitis and septicemia. Evidence points to a knowledge gap among parents, teenagers, and healthcare providers (HCPs) regarding IMD and available vaccines, including those against the highly prevalent serogroup B.

AREAS COVERED

An online survey was conducted between March 27 and April 12, 2019, to gather insights into the knowledge that parents/guardians have about IMD vaccines. The children were aged 2 months-10 years in Australia, Brazil, Germany, Greece, Italy, and Spain, 5-20 years in the UK, and 16-23 years in the US. The findings were discussed in the context of the available literature and solutions were proposed to minimize the knowledge gap and the barriers to vaccination against IMD.

EXPERT OPINION

The survey demonstrated that parents have a good understanding of IMD but a limited understanding of the different serogroups and vaccines. The available literature highlighted multiple barriers to IMD vaccine uptake; these may be reduced through education of HCPs, clear recommendations to parents by HCPs, the use of technology, and disease-awareness initiatives that engage parents through physical and digital channels. Further studies are warranted to assess the impact of the COVID-19 pandemic on IMD vaccination.

Temporal Relationships Between Saharan Dust Proxies, Climate, and Meningitis in Senegal

The Harmattan, a dry, northeasterly trade wind, transports large quantities of Saharan dust over the Sahelian region during the dry season (December-March). Studies have shown that bacterial meningitis outbreaks in Sahelian regions show hyper-endemic to endemic levels during high-dust months. We examine the (a) seasonality and intraseasonal variability of dust, climate, and meningitis and the (b) quantitative relationships between various dust proxies with meningitis lags of 0-10 weeks in Senegal from 2012 to 2017. The results show that the onset of the meningitis season occurs in February, roughly 2 months after the dusty season has begun. The meningitis season peaks at the beginning of April, when northeasterly wind speeds and particulate matter (PM) are relatively high, and the meningitis season ends near the end of June, when temperature and humidity rise and northeasterly wind speeds decline. Furthermore, we find that Senegal's relatively high humidity year-round may help slow the transmission of the infection, contributing to a lower disease incidence than landlocked countries in the meningitis belt. Lastly, our results suggest the desert dust may have a significant impact on the onset to the peak of the meningitis season in Senegal, particularly at the 0-2 and 10-week lag, whether that be directly through biological processes or indirectly through changes in human behavior. PM and visibility, however, are not in phase with aerosol optical depth throughout the year and consequently show different relationships with meningitis. This study further exemplifies the critical need for more PM, meteorological, and meningitis measurements in West Africa to further resolve these relationships.

Meningococcal A conjugate vaccine coverage in the meningitis belt of Africa from 2010 to 2021: a modelling study

BACKGROUND

As of the end of 2021, twenty-four countries in the African meningitis belt have rolled out mass campaigns of MenAfriVac®, a meningococcal A conjugate vaccine (MACV) first introduced in 2010. Twelve have completed introduction of MACV into routine immunisation (RI) schedules. Although select post-campaign coverage data are published, no study currently comprehensively estimates MACV coverage from both routine and campaign sources in the meningitis belt across age, country, and time.

METHODS

In this modelling study, we assembled campaign data from the twenty-four countries that had introduced any immunisation activity during or before the year 2021 (Benin, Burkina Faso, Burundi, Cameroon, Central African Republic, Chad, Côte d'Ivoire, Democratic Republic of the Congo, Ethiopia, Eritrea, the Gambia, Ghana, Guinea, Guinea Bissau, Kenya, Mali, Mauritania, Niger, Nigeria, Senegal, South Sudan, Sudan, Togo and Uganda) via WHO reports and RI data via systematic review. Next, we modelled RI coverage using Spatiotemporal Gaussian Process Regression. Then, we synthesized these estimates with campaign data into a cohort model, tracking coverage for each age cohort from age 1 to 29 years over time for each country.

FINDINGS

Coverage in high-risk locations amongst children aged 1-4 in 2021 was estimated to be highest in Togo with 96.0% (95% uncertainty interval [UI] 92.0-99.0), followed by Niger with 87.2% (95% UI 85.3-89.0) and Burkina Faso, with 86.4% (95% UI 85.1-87.6). These countries had high coverage values driven by an initial successful mass immunisation campaign, followed by a catch-up campaign, followed by introduction of RI. Due to the influence of older mass vaccination campaigns, coverage proportions skewed higher in the 1-29 age group than the 1-4 group, with a median coverage of 82.9% in 2021 in the broader age group compared to 45.6% in the narrower age group.

INTERPRETATION

These estimates highlight where gaps in immunisation remain and emphasise the need for broader efforts to strengthen RI systems. This methodological framework can be applied to estimate coverage for any vaccine that has been delivered in both routine and supplemental immunisation activities.

FUNDING

Bill and Melinda Gates Foundation.

Effect of Biannual Azithromycin to Children under 5 Years on the Carriage of Respiratory Pathogens among Children Aged 7-11 Years

In the MORDOR I trial, children under 5 years of age were randomized to receive biannual (every 6 months) azithromycin for 2 years in Niger, Malawi, and Tanzania. In 30 Nigerien communities, children aged 7-11 years, who were not enrolled in the MORDOR I trial to receive biannual azithromycin, were assessed for carriage of seven respiratory pathogens. We aimed to see whether there were effects on the carriage of these seven respiratory pathogens among 3,187 children aged 7-11 years living in the 30 communities via nasopharyngeal swabs collected at baseline (N = 1,066), as well as at year 1 (N = 1,019) and year 2 (N = 1,102)-each about 6 months after azithromycin or placebo treatment of children under age five. Most children were positive for Haemophilus influenzae (baseline: 83.8%; interquartile range [IQR]: 78.7-90.4) and Streptococcus pneumoniae (baseline: 82.9%; IQR: 74.2-86.8) at all time points regardless of treatment group. There were no differences in prevalence nor quantity of H. influenzae (prevalence ratio: 0.95; 95% CI: 0.90, 1.02), S. pneumoniae (prevalence ratio: 1.01; 95% CI: 0.96, 1.07), or any of the other respiratory pathogens in the treatment versus control groups at any time point. S. pneumoniae serotype 6AB (7.7%) and Neisseria meningitidis serotype W135 (24.9%) were the most prevalent serotypes detected among all positive S. pneumoniae and N. meningitidis samples, respectively. Biannual azithromycin did not reduce carriage of respiratory pathogens 6 months after the most recent round of biannual azithromycin among older nontreated children (aged 7-11 years) living in treatment communities.

Efficacy and Safety of Quadrivalent Conjugate Meningococcal Vaccines: A Systematic Review and Meta-Analysis

Over the last decades, different quadrivalent antimeningococcal vaccine formulations (diphteria toxoid conjugate, MenACWY-D; tetanus toxoid conjugate, MenACWY-TT; CRM₁₉₇ protein conjugate, MenACWY-CRM) have been developed. However, their availability varies, both in terms of authorized formulations and of inclusion in vaccination schedules. Furthermore, several countries include only the monovalent meningococcal C (MenC) vaccine in their immunization programmes. Finally, there is currently no updated systematic review that directly compares the MenACWY formulations. Thus, we summarized the evidence on efficacy and safety through four parallel, independent systematic literature reviews with meta-analysis which included randomized controlled trials comparing the abovementioned vaccines. A total of 16 studies have been included. In terms of efficacy, MenACWY-TT outperformed MenACWY-D and MenACWY-CRM for A, W-135, and Y serogroups, while no significant difference was found for serogroup C. Furthermore, we did not find significant differences in efficacy between MenC and MenACWY-TT. Regarding the safety, we were able to perform a quantitative analysis only between MenACWY-TT and MenC, finding no significant differences. Similarly, among the different MenACWY formulations no relevant differences were identified. These findings suggest that MenACWY-TT could be preferable to other formulations to improve current vaccination programs and to better develop future immunization policies.

Progress and Challenges in Bacterial Meningitis: A Review

IMPORTANCE

Bacterial meningitis is a worldwide health problem, with incidence rates ranging from approximately 0.9 per 100 000 individuals per year in high-income countries to 80 per 100 000 individuals per year in low-income countries. In low-income countries, bacterial meningitis has a mortality rate of up to 54%. Up to 24% of those who survive develop chronic neurological sequelae, such as hearing loss or focal neurological deficits.

OBSERVATIONS

Streptococcus pneumoniae causes about 72% and Neisseria meningitidis causes about 11% of cases of bacterial meningitis in people older than 16 years. Escherichia coli and Streptococcus agalactiae cause about 35% of cases of early-onset neonatal meningitis. In adults, risk factors for bacterial meningitis include older age and immunosuppressive conditions. The most common symptoms are headache (84%), fever (74%), stiff neck (74%), altered mental status (median [IQR] Glasgow Coma Scale score of 11 [9-14] on a scale ranging from 3-15), and nausea (62%). Brain imaging should be performed before lumbar puncture if patients present with altered mental status, focal neurological deficits, papilledema, or history of immunocompromising conditions or central nervous system disease. Bacterial meningitis should be suspected if any of the following are present on admission: serum leukocytes greater than 10.0 ×109/L, cerebrospinal fluid (CSF) leukocytes greater than 2000/μL, CSF granulocytes greater than 1180/μL, CSF protein greater than 2.2 g/L, CSF glucose less than 34.23 mg/dL, or fever. A positive Gram stain result for bacteria is diagnostic, but the sensitivity of a positive Gram stain result for bacterial meningitis ranges from 50% to 90%. In countries in which the prevalence of ceftriaxone-resistant Streptococcus pneumoniae exceeds 1%, vancomycin and ceftriaxone are the empirical antibiotics of choice, with the addition of ampicillin in neonates, older patients, and immunocompromised patients. Adjunctive dexamethasone should be used in patients with bacterial meningitis but stopped if Listeria monocytogenes is confirmed.

CONCLUSIONS AND RELEVANCE

Bacterial meningitis affects approximately 0.9 per 100 000 individuals to 80 per 100 000 individuals per year and has a mortality rate as high as 54%. First-line therapy is prompt empirical intravenous antibiotic therapy and adjunctive dexamethasone.

Improved sub-seasonal forecasts to support preparedness action for meningitis outbreak in Africa

West African countries are hit annually by meningitis outbreaks which occur during the dry season and are linked to atmospheric variability. This paper describes an innovative co-production process between the African Centre of Meteorological Applications for Development (ACMAD; forecast producer) and the World Health Organisation Regional Office for Africa (WHO AFRO; forecast user) to support awareness, preparedness and response actions for meningitis outbreaks. Using sub-seasonal to seasonal (S2S) forecasts, this co-production enables ACMAD and WHO AFRO to build initiative that increases the production of useful climate services in the health sector. Temperature and relative humidity forecasts are combined with dust forecasts to operationalize a meningitis early warning system (MEWS) across the African meningitis belt with a two-week lead time. To prevent and control meningitis, the MEWS is produced from week 1 to 26 of the year. This study demonstrates that S2S forecasts have good skill at predicting dry and warm atmospheric conditions precede meningitis outbreaks. Vigilance levels objectively defined within the MEWS are consistent with reported cases of meningitis. Alongside developing a MEWS, the co-production process provided a framework for analysis of climate and environmental risks based on reanalysis data, meningitis burden, and health service assessment, to support the development of a qualitative roadmap of country prioritization for defeating meningitis by 2030 across the WHO African region. The roadmap has enabled the identification of countries most vulnerable to meningitis epidemics, and in the context of climate change, supports plans for preventing, preparing, and responding to meningitis outbreaks.

CDC's COVID-19 International Vaccine Implementation and Evaluation Program and Lessons from Earlier Vaccine Introductions

The US Centers for Disease Control and Prevention (CDC) supports international partners in introducing vaccines, including those against SARS-CoV-2 virus. CDC contributes to the development of global technical tools, guidance, and policy for COVID-19 vaccination and has established its COVID-19 International Vaccine Implementation and Evaluation (CIVIE) program. CIVIE supports ministries of health and their partner organizations in developing or strengthening their national capacities for the planning, implementation, and evaluation of COVID-19 vaccination programs. CIVIE's 7 priority areas for country-specific technical assistance are vaccine policy development, program planning, vaccine confidence and demand, data management and use, workforce development, vaccine safety, and evaluation. We discuss CDC's work on global COVID-19 vaccine implementation, including priorities, challenges, opportunities, and applicable lessons learned from prior experiences with Ebola, influenza, and meningococcal serogroup A conjugate vaccine introductions.

Sustainable vaccine manufacturing in low- and middle-Income countries

The sustainable manufacturing of vaccines in developing countries is critical to increasing equitable access to vaccines and pandemic preparedness globally. Sustainable manufacturing requires that organizations engaged in the development, production and supply of vaccines have viable business models and incentives to manufacture vaccine products. The expanding manufacturing capabilities and capacities of developing countries vaccine manufacturers (DCVMs) are increasingly positioning these organizations to meet the national and regional public health needs in developing countries; however, key industry challenges such as regulatory barriers, low prices and demand uncertainty for vaccine products, and limited R&D funding threaten the long-term viability of vaccine manufacturers. This study assesses the technical capabilities, manufacturing capacities, and aspirational plans of DCVMs, exemplifying the business models and strategies undertaken to sustainably manufacture vaccines in developing countries. The public health importance of a healthy vaccine industry which enables manufacturers is discussed throughout. Vaccine manufacturers reported diverse product portfolios and R&D pipelines and utilized an array of vaccine technology platforms. Large manufacturing capacities were reported, a critical factor in manufacturers achieving economies of scale and supplying large volumes of vaccine doses to the world's most populous regions. Partnerships and collaboration within the industry and with international organizations along the vaccine value-chain were cited with high frequency. Manufacturers also reported aspirational plans to enter new markets, acquire new technologies and invest in the development of novel and improved vaccines. As DCVMs aim to have an increasing impact on the global vaccine ecosystem, a coordinated multi-stakeholder approach is required alleviate critical industry barriers to ensure that all efforts produce vaccines are sustainable and enable developing countries to realize the public health benefit of vaccines.

Preponderance of vaccine-preventable diseases hotspots in northern Ghana: a spatial and space-time clustering analysis from 2010 to 2014

BACKGROUND

Vaccine-preventable diseases (VPDs) persist globally with a disproportionately high burden in Low and Middle-Income Countries (LMICs). Although this might be partly due to the failure to sustain vaccination coverage above 90% in some WHO regions, a more nuanced understanding of VPD transmission beyond vaccination coverage may unveil other important factors in VPD transmission and control. This study identified VPDs hotspots and explored their relationships with ecology, urbanicity and land-use variations (Artisanal and Small-scale Gold Mining (ASGM) activities) in Ghana.

METHODS

District-level disease count data from 2010 to 2014 from the Ghana Health Service (GHS) and population data from the Ghana Population and Housing Census (PHC) were used to determine clustering patterns of six VPDs (Measles, Meningitis, Mumps, Otitis media, Pneumonia and Tetanus). Spatial and space-time cluster analyses were implemented in SaTScan using the discrete Poisson model. P-values were estimated using a combination of sequential Monte Carlo, standard Monte Carlo, and Gumbel approximations.

RESULTS

The study found a preponderance for VPD hotspots in the northern parts of Ghana and northernmost ecological zones (Sudan Savannah and Guinea Savannah). Incidence of meningitis was higher in the Sudan Savannah ecological zone relative to: Tropical Rain Forest (p = 0.001); Semi Deciduous Forest (p < 0.0001); Transitional Zone (p < 0.0001); Coastal Savannah (p < 0.0001) and Guinea Savannah (p = 0.033). Except for mumps, which recorded a higher incidence in urban districts (p = 0.045), incidence of the other five VPDs did not differ across the urban-rural divide. Whereas spatial analysis suggested that some VPD hotspots (tetanus and otitis media) occur more frequently in mining districts in the southern part of the country, a Mann-Whitney U test revealed a higher incidence of meningitis in non-mining districts (p = 0.019). Pneumonia and meningitis recorded the highest (722.8 per 100,000) and least (0.8 per 100,000) incidence rates respectively during the study period.

CONCLUSION

This study shows a preponderance of VPD hotspots in the northern parts of Ghana and in semi-arid ecoclimates. The relationship between ASGM activities and VPD transmission in Ghana remains blurred and requires further studies with better spatial resolution to clarify.

Translating diagnostics and drug delivery technologies to low-resource settings

Diagnostics and drug delivery technologies engineered for low-resource settings aim to meet their technical design specifications using strategies that are compatible with limited equipment, infrastructure, and operator training. Despite many preclinical successes, very few of these devices have been translated to the clinic. Here, we identify factors that contribute to the clinical success of diagnostics and drug delivery systems for low-resource settings, including the need to engage key stakeholders at an early stage, and provide recommendations for the clinical translation of future medical technologies.

Evaluation of Dried Blood and Cerebrospinal Fluid Filter Paper Spots for Storing and Transporting Clinical Material for the Molecular Diagnosis of Invasive Meningococcal Disease

To improve the storage and transport of clinical specimens for the diagnosis of Neisseria meningitidis (Nm) infections in resource-limited settings, we have evaluated the performance of dried blood spot (DBS) and dried cerebrospinal fluid spot (DCS) assays. DBS and DCS were prepared on filter paper from liquid specimens previously tested for Nm in the United Kingdom. Nm was detected and genogrouped by real-time PCR performed on crude genomic DNA extracted from the DBS (n = 226) and DCS (n = 226) specimens. Targeted whole-genome sequencing was performed on a subset of specimens, DBS (n = 4) and DCS (n = 6). The overall agreement between the analysis of liquid and dried specimens was (94.2%; 95% CI 90.8−96.7) for blood and (96.4%; 95% CI 93.5−98.0) for cerebrospinal fluid. Relative to liquid specimens as the reference, the DBS and DCS assays had sensitivities of (89.1%; 95% CI 82.7−93.8) and (94.2%; 95% CI 88.9−97.5), respectively, and both assays had specificities above 98%. A genogroup was identified by dried specimen analysis for 81.9% of the confirmed meningococcal infections. Near full-length Nm genome sequences (>86%) were obtained for all ten specimens tested which allowed determination of the sequence type, clonal complex, presence of antimicrobial resistance and other meningococcal genotyping. Dried blood and CSF filter spot assays offer a practical alternative to liquid specimens for the molecular and genomic characterisation of invasive meningococcal diseases in low-resource settings.

Enhancing Meningococcal Genomic Surveillance in the Meningitis Belt Using High-Resolution Culture-Free Whole-Genome Sequencing

Rollout of meningococcal serogroup A conjugate vaccine in Africa started in 2010, aiming to eliminate meningitis outbreaks, in meningitis belt countries. Since then, studies have been conducted, primarily using isolates, to assess the vaccine impact on the distribution of meningococcal strains in the region. Here, we implemented an innovative, culture-free whole-genome sequencing approach on almost 400 clinical specimens collected between 2017 and 2019 from meningococcal meningitis cases in 6 African countries. About 50% of specimens provided high-quality whole-genome sequence data for comprehensive molecular profiling of the meningococcal pathogen. Three major clonal complexes were identified: CC11 associated with serogroup W, CC181 associated with serogroup X, and CC10217 associated with serogroup C, which continues to rise as a predominant clonal complex in the region. Genomic surveillance for meningococcal meningitis can be significantly improved using culture-free methods to increase data representativeness and monitor changes in epidemiological landscape, especially for countries with low culture rate.

What drives willingness to receive a new vaccine that prevents an emerging infectious disease? A discrete choice experiment among university students in Uganda

Background

There is a critical need to identify the drivers of willingness to receive new vaccines against emerging and epidemic diseases. A discrete choice experiment is the ideal approach to evaluating how individuals weigh multiple attributes simultaneously. We assessed the degree to which six attributes were associated with willingness to be vaccinated among university students in Uganda.

Methods

We conducted a single-profile discrete choice experiment at Makerere University in 2019. Participants were asked whether or not they would be vaccinated in 8 unique scenarios where attributes varied by disease risk, disease severity, advice for or against vaccination from trusted individuals, recommendations from influential figures, whether the vaccine induced indirect protection, and side effects. We calculated predicted probabilities of vaccination willingness using mixed logistic regression models, comparing health professional students with all other disciplines.

Findings

Of the 1576 participants, 783 (49.8%) were health professional students and 685 (43.5%) were female. Vaccination willingness was high (78%), and higher among health students than other students. We observed the highest vaccination willingness for the most severe disease outcomes and the greatest exposure risks, along with the Minister of Health’s recommendation or a vaccine that extended secondary protection to others. Mild side effects and recommendations against vaccination diminished vaccination willingness.

Interpretation

Our results can be used to develop evidence-based messaging to encourage uptake for new vaccines. Future vaccination campaigns, such as for COVID-19 vaccines in development, should consider acknowledging individual risk of exposure and disease severity and incorporate recommendations from key health leaders.

Efficacy and Effectiveness of the Meningococcal Conjugate Group A Vaccine MenAfriVac® in Preventing Recurrent Meningitis Epidemics in Sub-Saharan Africa

For more than a century, epidemic meningococcal disease mainly caused by serogroup A Neisseria meningitidis has been an important public health problem in sub-Saharan Africa. To address this problem, an affordable meningococcal serogroup A conjugate vaccine, MenAfriVac®, was developed specifically for populations in the African meningitis belt countries. MenAfriVac® was licensed based on safety and immunogenicity data for a population aged 1-29 years. In particular, the surrogate markers of clinical efficacy were considered to be the higher immunogenicity and the ability to prime immunological memory in infants and young children compared to a polysaccharide vaccine. Because of the magnitude of serogroup A meningitis epidemics and the high morbidity and mortality burden, the World Health Organization (WHO) recommended the MenAfriVac® deployment strategy, starting with mass vaccination campaigns for 1-29-year-olds to rapidly interrupt serogroup A person-to-person transmission and establish herd protection, followed by routine immunization of infants and toddlers to sustain protection and prevent epidemics. After licensure and WHO prequalification of MenAfriVac®, campaigns began in December 2010 in Burkina Faso, Mali, and Niger. By the middle of 2011, it was clear that the vaccine was highly effective in preventing serogroup A carriage and disease. Post introduction meningitis surveillance revealed that serogroup A meningococcal disease had disappeared from all age groups, suggesting that robust herd immunity had been achieved.

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

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

Evaluating the Impact of Meningococcal Vaccines With Synthetic Controls

Invasive meningococcal disease (IMD) has a low and unpredictable incidence, presenting challenges for real-world evaluations of meningococcal vaccines. Traditionally, meningococcal vaccine impact is evaluated by predicting counterfactuals from pre-immunization IMD incidences, possibly controlling for IMD in unvaccinated age groups, but the selection of controls can influence results. We retrospectively applied a synthetic control (SC) method, previously used for pneumococcal disease, to data from 2 programs for immunization of infants against serogroups B and C IMD in England and Brazil. Time series of infectious/noninfectious diseases in infants and IMD cases in older unvaccinated age groups were used as candidate controls, automatically combined in a SC through Bayesian variable selection. SC closely predicted IMD in absence of vaccination, adjusting for nontrivial changes in IMD incidence. Vaccine impact estimates were in line with previous assessments. IMD cases in unvaccinated age groups were the most frequent SC-selected controls. Similar results were obtained when excluding IMD from control sets and using other diseases only, particularly respiratory diseases and measles. Using non-IMD controls may be important where there are herd immunity effects. SC is a robust and flexible method that addresses uncertainty introduced when equally plausible controls exhibit different post-immunization behaviors, allowing objective comparisons of IMD programs between countries.

Equity in vaccination policies to overcome social deprivation as a risk factor for invasive meningococcal disease

INTRODUCTION

Social deprivation is associated with poorer healthcare access. Vaccination is among the most effective public health interventions and achieving equity in vaccination access is vitally important. However, vaccines are often reimbursed by public funds only when recommended in national immunization programs (NIPs), which can increase inequity between high and low socioeconomic groups. Invasive meningococcal disease (IMD) is a serious vaccination-preventable disease. This review focuses on vaccination strategies against IMD designed to reduce inequity.

AREAS COVERED

We reviewed meningococcal epidemiology and current vaccination recommendations worldwide. We also reviewed studies demonstrating an association between social deprivation and risk of meningococcal disease, as well as studies demonstrating an impact of social deprivation on uptake of meningococcal vaccines. We discuss factors influencing inclusion of meningococcal vaccines in NIPs.

EXPERT OPINION

Incorporating meningococcal vaccines in NIPs is necessary to reduce inequity, but insufficient alone. Inclusion provides clear guidance to healthcare professionals and helps to ensure that vaccines are offered universally to all target groups. Beyond NIPs, cost of vaccination should be reimbursed especially for disadvantaged individuals. These approaches should help to achieve optimal protection against IMD, by increasing access and immunization rates, eventually reducing social inequities, and helping to protect those at greatest risk.

Neisseria meningitidis Serogroup C Clonal Complex 10217 Outbreak in West Kpendjal Prefecture, Togo 2019

Togo has reported seasonal meningitis outbreaks caused by non-Neisseria meningitidis serogroup A (NmA) pathogens since the introduction of meningococcal serogroup A conjugate vaccine (MACV, MenAfriVac) in 2014. From 2016 to 2017, NmW caused several outbreaks. In early 2019, a NmC outbreak was detected in the Savanes region of Togo and its investigation is described here. Under case-based surveillance, epidemiological and clinical data, and cerebrospinal fluid specimens were collected for every suspected case of meningitis. Specimens were tested for meningitis pathogens using confirmatory microbiological and molecular methods. During epidemic weeks 9 to 15, 199 cases were reported, with 179 specimens being available for testing and 174 specimens (97.2%) were tested by at least one confirmatory method. The NmC was the predominant pathogen confirmed (93.9%), belonging to sequence type (ST)-9367 of clonal complex (CC) 10217. All NmC cases were localized to the West Kpendjal district of the Savanes region with attack rates ranging from 4.1 to 18.8 per 100,000 population and case fatality rates ranging up to 2.2% during weeks 9 to 15. Of the 93 NmC confirmed cases, 63.4% were males and 88.2% were in the 5 to 29 age group. This is the first report of a NmC meningitis outbreak in Togo. The changing epidemiology of bacterial meningitis in the meningitis belt post-MACV highlights the importance of monitoring of emerging strain and country preparedness for outbreaks in the region.

IMPORTANCE The recent emergence of an invasive NmC strain in Togo is an example of the changing bacterial meningitis epidemiology in the meningitis belt post-MACV. The current epidemiology includes the regional circulation of various non-NmA serogroups, which emphasizes the need for effective molecular surveillance, laboratory diagnosis, and a multivalent vaccine that is effective against all serogroups in circulation.

Vaccines for International Pediatric Travelers

The pretravel management of the international pediatric traveler is based on provision of preventive education, chemoprophylaxis against malaria and traveler's diarrhea, as well as travel vaccinations. Immunization requirements are determined based on the traveler's pretravel immunization status, age, medical history, and destination. Immunization needs also vary depending on the exposures during the trip. Potential exposure to water, insects, or animals as well as duration of travel will help tailor risk avoidance education and travel immunizations. This review provides clinicians an overview of vaccines recommended for children traveling internationally.

The Epidemiology of Meningococcal Disease and Carriage, Genotypic Characteristics and Antibiotic Resistance of Neisseria meningitidis Isolates in Zhejiang Province, China, 2011–2021

Neisseria meningitidis (Nm) remains a worldwide leading cause of epidemic meningitis. During 2011–July 2021, 55 meningococcal disease (MD) cases were reported with a case fatality rate of 5.45% in Zhejiang Province, China. The median age was 7 years. The annual incidence was 0.0017–0.0183 per 100,000 population. The highest age-specific incidence was observed in the group younger than 1 year. Serogroup was identified in 30 laboratory-confirmed MD cases, and MenB was most predominant. MenB was mainly observed in two age groups: younger than 5 and older than 35 years. MenB incidence was significantly increasing from 0.0018 per 100,000 in 2013 to 0.0070 per 100,000 in 2019. During 2015–2020, 17 positive samples were detected from 2,827 throat swabs from healthy population, of which 70.59% was MenB. Twenty multilocus sequence typing sequence types (STs) containing eight newly assigned STs (ST15881–ST15888) were determined in all Nm isolates. Either in MD cases or in healthy population, MenB CC ST-4821 was the predominant ST. It was worth noting that two MenY CC ST-23 cases occurred in 2019 and 2021, respectively. MenY CC ST-23 MD cases increased gradually in China. Phylogeny results based on genome sequencing indicated that Chinese MenW CC ST-11 isolates were genetically linked and grouped together with Japanese isolates, separated from MenW CC ST-11 isolates from Saudi Arabia Hajj outbreak, Europe, South Africa, South America, North America, and Oceania. MenW CC ST-11 isolates from East Asia might have evolved locally. Antibiotic susceptibility tests revealed a relatively high resistance rate (22.86%) of Nm isolates to penicillin. This study provided valuable data for Chinese public health authorities to grasp the temporal epidemiological characteristics of MD and healthy carriage.

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

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

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

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

Outcome of childhood bacterial meningitis on three continents

Our objective was to quantify the differences in the outcomes from childhood bacterial meningitis (BM) and to describe the factors associated with them in different parts of the world. This study is a secondary analysis of prospectively collected data from five clinical BM trials conducted in Finland, Latin America (LatAm), and Angola between 1984 and 2017. As all data were collected uniformly, direct comparison of the series was possible. Associations between patient characteristics and death or dismal outcome—the triad of death, severe neurological sequelae, or deafness—were explored. In all, data on 2123 children with BM were analyzed. Etiology was confirmed in 95%, 83%, and 64%, in Finland, LatAm and Angola, respectively. The leading agents were Haemophilus influenzae, Streptococcus pneumoniae, and Neisseria meningitidis. Dismal outcome was the end result for 54%, 31%, and 5% of children in Angola, LatAm, and Finland, respectively. Although underweight, anemia, and tardy arrival worsened prognoses in Angola and LatAm, it was the presenting condition that was central in terms of outcome. In multivariate analysis, the factors independently associated with dismal outcome were the study site (Angola vs. Finland, OR 11.91, 95% CI 5.54–25.63, p < 0.0001 or LatAm vs. Finland, OR 9.46, 95% CI 4.35–20.61, p < 0.0001), Glasgow Coma Score < 13 (OR 4.58, 95% CI 3.31–6.32, p < 0.0001), seizures (OR 1.96, 95% CI 1.43–2.69), age < 1 year (OR 1.55, 95% CI 1.13–2.14, p = 0.007), and pneumococcal etiology (OR 1.49, 95% CI 1.08–2.06, p = 0.015). Greatly dissimilar outcomes from BM reflected the findings on admission on all three continents. Optimizing growth, preventing anemia, and prompt treatment may improve outcomes in resource poor areas.

Elucidating the Structural and Minimal Protective Epitope of the Serogroup X Meningococcal Capsular Polysaccharide

Despite the considerable progress toward the eradication of meningococcal disease with the introduction of glycoconjugate vaccines, previously unremarkable serogroup X has emerged in recent years, recording several outbreaks throughout the African continent. Different serogroup X polysaccharide-based vaccines have been tested in preclinical trials, establishing the principles for further improvement. To elucidate the antigenic determinants of the MenX capsular polysaccharide, we generated a monoclonal antibody, and its bactericidal nature was confirmed using the rabbit serum bactericidal assay. The antibody was tested by the inhibition enzyme-linked immunosorbent assay and surface plasmon resonance against a set of oligosaccharide fragments of different lengths. The epitope was shown to be contained within five to six α-(1–4) phosphodiester mannosamine repeating units. The molecular interactions between the protective monoclonal antibody and the MenX capsular polysaccharide fragment were further detailed at the atomic level by saturation transfer difference nuclear magnetic resonance (NMR) spectroscopy. The NMR results were used for validation of the in silico docking analysis between the X-ray crystal structure of the antibody (Fab fragment) and the modeled hexamer oligosaccharide. The antibody recognizes the MenX fragment by binding all six repeating units of the oligosaccharide via hydrogen bonding, salt bridges, and hydrophobic interactions. In vivo studies demonstrated that conjugates containing five to six repeating units can produce high functional antibody levels. These results provide an insight into the molecular basis of MenX vaccine-induced protection and highlight the requirements for the epitope-based vaccine design.

An overview of bacterial meningitis epidemics in Africa from 1928 to 2018 with a focus on epidemics "outside-the-belt"

Background

Bacterial meningitis occurs worldwide but Africa remains the most affected continent, especially in the "Meningitis belt" that extends from Senegal to Ethiopia. Three main bacteria are responsible for causing bacterial meningitis, i.e., N. meningitidis (Nm), S. pneumoniae and H. influenzae type b. Among Nm, serogroup A used to be responsible for up to 80 to 85% of meningococcal meningitis cases in Africa. Since 2000, other Nm serogroups including W, X and C have also been responsible for causing epidemics. This overview aims to describe the main patterns of meningitis disease cases and pathogens from 1928 to 2018 in Africa with a special focus on disease conditions “out-of-the-belt” area that is still usually unexplored. Based on basic spatio-temporal methods, and a 90-years database of reported suspected meningitis cases and death from the World Health Organization, we used both geographic information system and spatio-temporal statistics to identify the major localizations of meningitis epidemics over this period in Africa.

Results

Bacterial meningitis extends today outside its historical limits of the meningitis belt. Since the introduction of MenAfrivac vaccine in 2010, there has been a dramatic decrease in NmA cases while other pathogen species and Nm variants including NmW, NmC and Streptococcus pneumoniae have become more prevalent reflecting a greater diversity of bacterial strains causing meningitis epidemics in Africa today.

Conclusion

Bacterial meningitis remains a major public health problem in Africa today. Formerly concentrated in the region of the meningitis belt with Sub-Saharan and Sudanian environmental conditions, the disease extends now outside these historical limits to reach more forested regions in the central parts of the continent. With global environmental changes and massive vaccination targeting a unique serogroup, an epidemiological transition of bacterial meningitis is ongoing, requiring both a better consideration of the etiological nature of the responsible agents and of their proximal and distal determinants.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-021-06724-1.

Community-acquired bacterial meningitis

Progress has been made in the prevention and treatment of community-acquired bacterial meningitis during the past three decades but the burden of the disease remains high globally. Conjugate vaccines against the three most common causative pathogens (Streptococcus pneumoniae, Neisseria meningitidis, and Haemophilus influenzae) have reduced the incidence of disease, but with the replacement by non-vaccine pneumococcal serotypes and the emergence of bacterial strains with reduced susceptibility to antimicrobial treatment, meningitis continues to pose a major health challenge worldwide. In patients presenting with bacterial meningitis, typical clinical characteristics (such as the classic triad of neck stiffness, fever, and an altered mental status) might be absent and cerebrospinal fluid examination for biochemistry, microscopy, culture, and PCR to identify bacterial DNA are essential for the diagnosis. Multiplex PCR point-of-care panels in cerebrospinal fluid show promise in accelerating the diagnosis, but diagnostic accuracy studies to justify routine implementation are scarce and randomised, controlled studies are absent. Early administration of antimicrobial treatment (within 1 hour of presentation) improves outcomes and needs to be adjusted according to local emergence of drug resistance. Adjunctive dexamethasone treatment has proven efficacy beyond the neonatal age but only in patients from high-income countries. Further progress can be expected from implementing preventive measures, especially the development of new vaccines, implementation of hospital protocols aimed at early treatment, and new treatments targeting checkpoints of the inflammatory cascade.

Toward Establishing Integrated, Comprehensive, and Sustainable Meningitis Surveillance in Africa to Better Inform Vaccination Strategies

Large populations across sub-Saharan Africa remain at risk of devastating acute bacterial meningitis epidemics and endemic disease. Meningitis surveillance is a cornerstone of disease control, essential for describing temporal changes in disease epidemiology, the rapid detection of outbreaks, guiding vaccine introduction and monitoring vaccine impact. However, meningitis surveillance in most African countries is weak, undermined by parallel surveillance systems with little to no synergy and limited laboratory capacity. African countries need to implement comprehensive meningitis surveillance systems to adapt to the rapidly changing disease trends and vaccine landscapes. The World Health Organization and partners have developed a new investment case to restructure vaccine-preventable disease surveillance. With this new structure, countries will establish comprehensive and sustainable meningitis surveillance systems integrated with greater harmonization between population-based and sentinel surveillance systems. There will also be stronger linkage with existing surveillance systems for vaccine-preventable diseases, such as polio, measles, yellow fever, and rotavirus, as well as with other epidemic-prone diseases to leverage their infrastructure, transport systems, equipment, human resources and funding. The implementation of these concepts is currently being piloted in a few countries in sub-Saharan Africa with support from the World Health Organization and other partners. African countries need to take urgent action to improve synergies and coordination between different surveillance systems to set joint priorities that will inform action to control devastating acute bacterial meningitis effectively.

The Global Landscape of Pediatric Bacterial Meningitis Data Reported to the World Health Organization-Coordinated Invasive Bacterial Vaccine-Preventable Disease Surveillance Network, 2014-2019

BACKGROUND

The World Health Organization (WHO) coordinates the Global Invasive Bacterial Vaccine-Preventable Diseases (IB-VPD) Surveillance Network to support vaccine introduction decisions and use. The network was established to strengthen surveillance and laboratory confirmation of meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis.

METHODS

Sentinel hospitals report cases of children <5 years of age hospitalized for suspected meningitis. Laboratories report confirmatory testing results and strain characterization tested by polymerase chain reaction. In 2019, the network included 123 laboratories that follow validated, standardized testing and reporting strategies.

RESULTS

From 2014 through 2019, >137 000 suspected meningitis cases were reported by 58 participating countries, with 44.6% (n = 61 386) reported from countries in the WHO African Region. More than half (56.6%, n = 77 873) were among children <1 year of age, and 4.0% (n = 4010) died among those with reported disease outcome. Among suspected meningitis cases, 8.6% (n = 11 798) were classified as probable bacterial meningitis. One of 3 bacterial pathogens was identified in 30.3% (n = 3576) of these cases, namely S. pneumoniae (n = 2177 [60.9%]), H. influenzae (n = 633 [17.7%]), and N. meningitidis (n = 766 [21.4%]). Among confirmed bacterial meningitis cases with outcome reported, 11.0% died; case fatality ratio varied by pathogen (S. pneumoniae, 12.2%; H. influenzae, 6.1%; N. meningitidis, 11.0%). Among the 277 children who died with confirmed bacterial meningitis, 189 (68.2%) had confirmed S. pneumoniae. The proportion of pneumococcal cases with pneumococcal conjugate vaccine (PCV) serotypes decreased as the number of countries implementing PCV increased, from 77.8% (n = 273) to 47.5% (n = 248). Of 397 H. influenzae specimens serotyped, 49.1% (n = 195) were type b. Predominant N. meningitidis serogroups varied by region.

CONCLUSIONS

This multitier, global surveillance network has supported countries in detecting and serotyping the 3 principal invasive bacterial pathogens that cause pediatric meningitis. Streptococcus pneumoniae was the most common bacterial pathogen detected globally despite the growing number of countries that have nationally introduced PCV. The large proportions of deaths due to S. pneumoniae reflect the high proportion of meningitis cases caused by this pathogen. This global network demonstrated a strong correlation between PCV introduction status and reduction in the proportion of pneumococcal meningitis infections caused by vaccine serotypes. Maintaining case-based, active surveillance with laboratory confirmation for prioritized vaccine-preventable diseases remains a critical component of the global agenda in public health.The World Health Organization (WHO)-coordinated Invasive Bacterial Vaccine-Preventable Disease (IB-VPD) Surveillance Network reported data from 2014 to 2019, contributing to the estimates of the disease burden and serotypes of pediatric meningitis caused by Streptococcus pneumoniae, Haemophilus influenzae and Neisseria meningitidis.

Pneumococcal Meningitis Outbreaks in Africa, 2000-2018: Systematic Literature Review and Meningitis Surveillance Database Analyses

BACKGROUND

The meningitis belt of sub-Saharan Africa has traditionally experienced large outbreaks of meningitis mainly caused by Neisseria meningitidis. More recently, Streptococcus pneumoniae has been recognized as a cause of meningitis outbreaks in the region. Little is known about the natural history and epidemiology of these outbreaks, and, in contrast to meningococcal meningitis, there is no agreed definition for a pneumococcal meningitis epidemic. The aim of this analysis was to systematically review and understand pneumococcal meningitis outbreaks in Africa between 2000 and 2018.

METHODS

Meningitis outbreaks were identified using a systematic literature review and analyses of meningitis surveillance databases. Potential outbreaks were included in the final analysis if they reported at least 10 laboratory-confirmed meningitis cases above baseline per week with ≥50% of cases confirmed as pneumococcus.

RESULTS

A total of 10 potential pneumococcal meningitis outbreaks were identified in Africa between 2000 and 2018. Of these, 2 were classified as confirmed, 7 were classified as possible, and 1 was classified as unlikely. Three outbreaks spanned more than 1 year. In general, the outbreaks demonstrated lower peak attack rates than meningococcal meningitis outbreaks and had a predominance of serotype 1. Patients with pneumococcal meningitis tended to be older and had higher case fatality rates than meningococcal meningitis cases. An outbreak definition, which includes a weekly district-level incidence of at least 10 suspected cases per 100 000 population per week, with >10 cumulative confirmed cases of pneumococcus per year, would have identified all 10 potential outbreaks.

CONCLUSIONS

Given the frequency of and high case fatality from pneumococcal meningitis outbreaks, public health recommendations on vaccination strategies and the management of outbreaks are needed. Improved laboratory testing for S. pneumoniae is critical for early outbreak identification.

The Epidemiology of Invasive Meningococcal Disease in the Kingdom of Saudi Arabia: A Narrative Review with Updated Analysis

Reducing invasive meningococcal disease (IMD) through MenACWY immunization is a critical healthcare strategy in the Kingdom of Saudi Arabia (KSA). Robust IMD surveillance is essential to help assess the need for additional immunization initiatives in target populations. This is particularly important in KSA, where mass gatherings accompanying Hajj/Umrah pilgrimages have been associated with IMD outbreaks within the local KSA population, and subsequent intercontinental spread via returning pilgrims. This narrative review of the published literature describes the changing epidemiology of IMD in KSA to provide a perspective on the impact of current immunization strategies and potential gaps. As recent published surveillance data are lacking, we also evaluated publicly reported data from the KSA Ministry of Health (MoH) for 2012–2019 to inform more recent IMD trends. Between 1995 and 2011, national surveillance data indicate that 1103 IMD cases were reported in KSA: 60% in 2000–2001, involving two (mainly MenW) outbreaks involving KSA citizens/residents and pilgrims focused in Mecca and Medina. Across 2002–2011, 184 cases of IMD were reported, with a higher proportion occurring in KSA citizens/residents, and with less focus within pilgrimage centers than apparent in previous years. Our analysis of MoH data found that, between 2012 and 2019, 44 IMD cases were reported, all in KSA citizens/residents, and chiefly in children or infants. No pilgrimage-associated outbreaks have occurred since 2001. Serogroup data were available for 62.5% of all cases for 2002–2011; MenW (40.0%), MenA (35.7%), and MenB (16.5%). Serogroup data for 2012–2019 remain incompletely reported, and the existing surveillance system could be improved, as some element of underestimation/underreporting of IMD may exist. While existing MenACWY immunization strategies for KSA citizens/residents and visiting pilgrims have been successful in reducing IMD due to specific serogroups, disease due to MenB remains a potential risk, and additional immunization strategies should be considered.

National control laboratory independent lot testing of COVID-19 vaccines: the UK experience

The past 18 months have seen an unprecedented approach to vaccine development in the global effort against the COVID-19 pandemic. The process from discovery research, through clinical trials and regulatory approval often takes more than 10 years. However, the critical need to expedite vaccine availability in the pandemic has meant that new approaches to development, manufacturing, and regulation have been required: this has necessitated many stages of product development, clinical trials, and manufacturing to be undertaken in parallel at a global level. Through the development of these innovative products, the world has the best chance of finding individual, or combinations of, vaccines that will provide adequate protection for the world’s population. Despite the huge scientific and regulatory achievements and significant investment to accelerate vaccine availability, it is essential that safety measures are not compromised. Here we focus on the post regulatory approval testing by independent laboratories that provides an additional assurance of the safety and quality of a product, with an emphasis on the UK experience through the National Institute for Biological Standards and Control (NIBSC), an expert centre of the UK’s Medicines and Healthcare products Regulatory Agency (MHRA).

Neisseria meningitidis serogroup W(P1.5-2) sepsis presenting with myopericarditis in an elderly previously healthy male

A rare complication of Neisseria meningitidis is pericarditis. Here a 74-year-old male with Neisseria meningitidis serogroup W(P1.5−2) presented with myopericarditis. The patient developed cardiac tamponade and a pericardiocentesis was subsequently performed. The patient also developed a duodenal perforation, possibly secondary to the stress from being critically ill. The patient fully recovered.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL TRIALS REGISTRATION

CRD42018082085 (PROSPERO).