Meningococcal disease epidemiology in Brazil (2005-2018) and impact of MenC vaccination

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.

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.

Genomic characterization of invasive meningococcal X isolates from Brazil, 1992-2022

INTRODUCTION

Invasive meningococcal disease (IMD) is a major health problem. Given the post-COVID-19 pandemic scenario with the loosening of the non-pharmacological measures to control the virus transmission and considering the observed global reduction of meningococcal vaccination coverage, an increase in IMD cases can be expected.

METHODOLOGY

Using whole-genome sequencing, we characterized six Neisseria meningitidis serogroup X (MenX) isolates recovered from IMD cases in Brazil in the last 30 years.

RESULTS

The predominance (66.6%, 4/6) of ST2888 presenting fHbp 160, NHBA 129, NadA 21, and PorA 19,15 was found on isolates. Two novel STs, 15458 and 15477, were described.

CONCLUSION

This study describes the circulation of MenX lineage ST2888 in Brazil, previously reported only in Europe. Continuous universal surveillance is crucial to implement prompt public health measures aiming to prevent and control non-vaccine preventable serogroup X IMD cases.

Comparing the meningococcal serogroup C immune response elicited by a tetanus toxoid conjugate quadrivalent meningococcal vaccine (MenACYW-TT) versus a quadrivalent or monovalent C tetanus toxoid conjugate meningococcal vaccine in healthy meningococcal vaccine-naïve toddlers: A randomised, controlled trial

MenACYW-TT (MenQuadfi®) is a quadrivalent meningococcal tetanus toxoid conjugate vaccine licensed in Europe for use in individuals ≥12 months. This study assessed whether serogroup C immune responses with MenACYW-TT were at least non-inferior, or superior, to those of quadrivalent meningococcal ACWY (MCV4-TT; Nimenrix®) and monovalent meningococcal C (MenC-TT; NeisVac-C®) vaccines in toddlers (12–23 months). In this modified, double-blind Phase III study (NCT03890367), 701 toddlers received one dose of MenACYW-TT (n = 230), MCV4-TT (n = 232) or MenC-TT (n = 239). Serum bactericidal assays with human (hSBA) and baby rabbit (rSBA) complement were used to measure anti-meningococcal serogroup C antibodies at baseline and 30 days post-vaccination. A sequential statistical approach was used for primary and secondary objectives. For the primary objectives, superiority of serogroup C was assessed in terms of hSBA seroprotection rates (defined as titers ≥1:8) and GMTs for MenACYW-TT compared to MCV4-TT, and rSBA GMTs compared to MenC-TT. The safety of all vaccines within 30 days post-vaccination was described. When administered as a single dose to meningococcal vaccine-naïve healthy toddlers the superiority of the MenACYW-TT serogroup C immune response versus MCV4-TT was demonstrated for hSBA GMTs (ratio 16.3 [12.7–21.0]) and seroprotection (difference 10.43% [5.68–16.20]); and versus MenC-TT in terms of rSBA GMTs (ratio 1.32 [1.06–1.64]). The safety profiles of a single dose of MenACYW-TT, MCV4-TT and MenC-TT were similar. In meningococcal vaccine-naïve toddlers, MenACYW-TT induced superior immune responses to serogroup C versus MCV4-TT in terms of hSBA seroprotection and GMTs and versus MenC-TT in terms of rSBA GMTs.

Impact of COVID-19 pandemic on vaccination against meningococcal C infection in Brazil

Objective

Analyzing the impact of COVID-19 pandemic on meningococcal C conjugate vaccination in Brazil.

Methods

Ecological study, based on interrupted time series, carried out with data collected through the Information System of the National Immunization Program (IS-NIP). Collected data refer to the number of meningococcal C conjugate vaccine doses administered from March 2019 to December 2020.

Results

In total, 14,832,054 meningococcal C conjugate vaccine doses were administered throughout the investigated period; 66.30% of them, from March 2019 to February 2020 and 33.70%, from March to December 2020. Statistically significant steps were observed, i.e., the COVID-19 pandemic had negative impact on the number of MenC vaccine doses administered in the North and South regions (26,98% and 41.47%, respectively) and in the eleven Brazilian States.

Conclusion

The current study has shown that the COVID-19 pandemic had negative impact on the number of MenC vaccine doses administered in the Northern and Southern Brazil, and in eleven Brazilian states. Among all challenges experienced during the COVID-19 pandemic, one finds reduced MenC vaccine coverage, which, consequently, may lead to increased meningococcal infection rates in Brazil.

Emergence of Neisseria meningitidis W South American sublineage strain variant in Brazil: disease and carriage

Introduction. Invasive meningococcal disease is a major health problem, impacting morbidity and mortality worldwide. Exploratory genomics has revealed insights into adaptation, transmissibility and virulence to elucidate endemic, outbreaks or epidemics caused by Neisseria meningitidis serogroup W (MenW) strains.Gap Statement. Limited information on the genomics of Neisseria meningitis serogroup W ST11/cc11 is available from emerging countries, especially in contemporary isolates.Aim. To (i) describe the antigenic diversity and distribution of genetic lineages of N. meningitidis serogroup W circulating in Brazil; (ii) study the carriage prevalence of hypervirulent clones in adolescents students and (iii) analyse the potential risk factors for meningococcal carriage.Methodology. Using whole-genome sequencing, we analysed the genomic diversity of 92 invasive N. meningitidis serogroup W isolates circulating in Brazil from 2016 to 2019. A cross-sectional survey of meningococcal carriage was conducted in 2019, in the city of Florianópolis, Brazil, among a representative sample of 538 students.Results. A predominance (58.5 %, 41/82) of ST11/cc11 presenting PorB2-144, PorA VR1-5, VR2-2, FetA 1-1, and a novel fHbp peptide 1241 was found on invasive N. meningitidis W isolates, on the other hand, a high diversity of clonal complexes was found among carriage isolates. The overall carriage rate was 7.5 % (40/538). A total of 28 of 538 swab samples collected were culture positive for N. meningitidis, including four serogroup/genogroup B isolates (14.8 %;4/27), 1 serogroup/genogroup Y isolate (3.7 %;1/27), 22 (81.5 %; 22/27) non-groupable isolates. No MenW isolate was identified among carriages isolates.Conclusion. This report describes the emergence of the new MenW ST11/cc11 South America sublineage variant, named here, 2016 strain, carrying a novel fHbp peptide 1241, but its emergence, was not associated with an increased MenW carriage prevalence. Continuous surveillance is necessary to ascertain the role of this sublineage diversification and how its emergence can impact transmission.

Impact of meningococcal C conjugate vaccine on incidence of invasive meningococcal disease in an 18-year time-series in Brazil and in distinct Brazilian regions

OBJECTIVE

To evaluate the impact of meningococcal C conjugate (MCC) vaccine in Brazil.

METHODS

Ecological study assessing all invasive meningococcal disease (IMD) and meningococcal C disease (MenC) cases reported in all age groups, from 2001 to 2019. MCC was implemented in 2010. Data were collected on the DATASUS platform. Joinpoint regression was performed to assess the Annual Percent Change (APC) of the incidence rate.

RESULTS

IMD incidence decreased in all Brazilian regions from 2001 onwards, without apparent additional reduction attributable to MCC vaccine in the North, Northeast and South. The higher and statistically significant APC reduction in all age groups, in the North and South, and in children <5 years, in the Northeast, occurred between 2001-2011 (-15.4%), 2004-2012 (-14.4%), and 2001-2013 (-10.3%), respectively, before MCC vaccine implementation. Annual incidence of MenC in under 5 years significantly fell in the North (-6.8%; 2011-2018), Southeast (-40.6%; 2010-2015) and Midwest (-48.6%; 2010-2014), which may be attributable to MCC implementation.

CONCLUSION

IMD and MenC behaved differently after MCC vaccine implementation in Brazil during this 18-year time-series analysis. This suggests that the control of IMD should be based on multiple public health care measures and considered on a regional basis.

Surveillance and control of meningococcal disease in the COVID-19 era: A Global Meningococcal Initiative review

This review article incorporates information from the 4th Global Meningococcal Initiative summit meeting. Since the introduction of stringent COVID-19 infection control and lockdown measures globally in 2020, there has been an impact on IMD prevalence, surveillance, and vaccination compliance. Incidence rates and associated mortality fell across various regions during 2020. A reduction in vaccine uptake during 2020 remains a concern globally. In addition, several Neisseria meningitidis clonal complexes, particularly CC4821 and CC11, continue to exhibit resistance to antibiotics, with resistance to ciprofloxacin or beta-lactams mainly linked to modifications of gyrA or penA alleles, respectively. Beta-lactamase acquisition was also reported through horizontal gene transfer (bla_ROB-1) involving other bacterial species. Despite the challenges over the past year, progress has also been made on meningococcal vaccine development, with several pentavalent (serogroups ABCWY and ACWYX) vaccines currently being studied in late-stage clinical trial programmes.

Development and Immunogenicity of a Brazilian Glycoconjugate vaccine against Meningococcal W in a Pilot Scale

Recent changes in the epidemiology of meningococcal have been reported and meningococcal group W (MenW) has become the third most prevalent group isolated in Brazil in the last 10 years. In this study we have developed a conjugate vaccine for MenW using a modified reductive amination conjugation method through a covalent linkage between periodate-oxidized MenW non-O-acetylated polysaccharide and hydrazide-activated monomeric tetanus toxoid. Process control of bulks was done by physicochemical analysis including polysaccharide and protein quantification, high performance liquid chromatography - size exclusion chromatography, capillary electrophoresis, and hydrogen nuclear magnetic resonance. Conjugate bulks were best produced with concentration of polysaccharide twice as high as protein, at room temperature, and pH approximately 6.0. A scaled-up bulk (100 mg scale) was formulated and inoculated intramuscularly in mice in a dose-response study (0.1, 0.5, 1.0 and 10.0 µg of polysaccharide/dose). The immunogenicity of conjugate bulks was determined by serum bactericidal assay and ELISA assays of serum from immunized mice. ELISA and SBA titers revealed high titers of IgG and demonstrated the functionality of the antibodies produced in all doses studied 15 days after the third dose. However, significant differences were observed among them by ELISA. In conclusion, this study established the best conditions to produce MenW conjugate bulks and showed the efficacy of the obtained conjugate bulk in induce a good immune response in mice. Further experiments will need to be done to scale up the conjugation reaction and then allow the use of this conjugate in clinical trials.