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Introduction: Following the CHAMPION-NMOSD trial, the FDA recently granted approval for ravulizumab, a humanized monoclonal antibody against complement C5 protein in AQP-4 seropositive neuromyelitis optica spectrum disorder (NMOSD). Similar to eculizumab, ravulizumab offers near-complete prevention of NMOSD relapses, but has a longer half-life, providing decreased infusion frequency and increased convenience for patients. While targeting the complement pathway has clear advantages, patients are at risk for infection with encapsulated organisms, in particular Neisseria meningitidis ., Areas Covered: In this paper, we discuss the details of the CHAMPION-NMOSD trial and discuss challenges in meningitis prevention and strategies for switching therapies., Expert Opinion: Ravulizumab improves on eculizumab's success as a highly effective NMOSD therapy by decreasing infusion frequency, thereby increasing patient convenience. We predict that ravulizumab will eventually replace eculizumab but may not have a similar impact on inebelizumab or satralizumab. Patients taking C5 complement inhibitors have an increased risk of serious meningococcal infections, such as invasive meningococcal disease (IMD), and have incomplete protection against IMD despite immunization. Thus, we recommend that in addition to standard pre-immunizations against Neisseria meningitidis , patients should also be assessed for starting on appropriate antibiotic prophylaxis against IMD, based on local resistance patterns.

In Western Europe, many countries have robust and well-established surveillance systems and case reporting mechanisms. IMD incidence across Western Europe is low with a predominance of meningococcal serogroup B (MenB). Case confirmation and antimicrobial susceptibility testing is often standardised in this region, with many countries also having robust vaccination programmes in place. Both MenB and MenACWY vaccines form part of National Immunisation Programmes (NIPs) in most European countries, with Sweden only offering vaccination in special circumstances. Despite these established programmes, there remains a critical need for advocacy efforts in affecting change in diagnosis, testing, and treatment. Recent campaigns, such as the World Meningitis Day digital toolkit, have helped raise awareness and draw attention to meningococcal disease. Awareness around antibiotic resistance has also led to the identification of antibiotic-resistant meningococcal strains, with an increase, albeit small, in these strains noted across the region. Countries such as Spain, Portugal, Germany, Switzerland, and France have either reported strains resistant to penicillin, ciprofloxacin and/or isolates with a reduced susceptibility to third-generation cephalosporins., Competing Interests: Declaration of Competing Interest Ray Borrow performs contract research on behalf of UKHSA for GSK, PATH, Pfizer and Sanofi. Heike Claus has received personal fee for scientific presentation for Sanofi. Ener Cagri Dinleyici performs contract work for the Eskisehir Osmangazi University funded by GSK, Sanofi Pasteur and Pfizer. Lee Harrison has served on advisory boards and/or made scientific presentations for GSK, Pfizer, Sanofi, and Merck, for which he does not receive any personal fees. William P. Hausdorff has served on advisory boards for Sanofi, Merck, and Vaxcyte, for which he does not receive any personal fees or reimbursement. Corinne Levy reports personal fees for advisory board and scientific presentations for MSD and Pfizer. Wesley Mattheus reports research grants funded by GSK and Pfizer. Marco A. P. Sáfadi reports research grants and personal fees for advisory boards from GSK, Pfizer, and Sanofi. Vinny Smith works for Meningitis Research Foundation that receives income from grants, sponsorship and consultancy income from GSK, MSD, Pfizer, Sanofi and Serum Institute of India. M.K. Taha performs contract work for the Institut Pasteur funded by GSK, Pfizer and Sanofi. M.K. Taha and A-E Deghmane have a patent NZ630133A Patent with GSK “Vaccines for serogroup X meningococcus” issued. Georgina Tzanakaki reports contract work on behalf of the University of West Attica as participation on advisory boards and scientific presentations for Pfizer, Sanofi and Merck. J.A. Vázquez performs contract work for the Institute of Health Carlos III funded by GSK and Pfizer and he has received personal fees from Pfizer and Sanofi. Nina van Sorge receives fee for service and presentations (directly paid to the institution) from MSD and GSK. Finnish Institute for Health and Welfare has received research funding from Pfizer and GSK for projects in which Maija Toropainen has acted as a researcher without personal remuneration., (Crown Copyright © 2024. Published by Elsevier Ltd. All rights reserved.)

Genome-wide association studies (GWAS) with binary or single phenotype data have successfully identified disease-associated genotypes and determinants of antimicrobial resistance. We describe a novel phenotype-to-genotype approach for a major bacterial pathogen that involves simultaneously testing for associations among multiple disease-related phenotypes and linkages between phenotypic variation and genetic determinants. High-throughput assays quantified variation among 163 Neisseria meningitidis serogroup W ST-11 clonal complex isolates for 11 phenotypic traits. A comparison of carriage and two disease subgroups detected significant differences between groups for eight phenotypic traits. Candidate genotypic testing indicated that indels in csw , a capsular biosynthesis gene, were associated with reduced survival in antibody-depleted heat-inactivated serum. GWAS testing detected 341 significant genetic variants (3 single-nucleotide polymorphisms and 338 unitigs) across all traits except serum bactericidal antibody-depleted assays. Growth traits were associated with variants of capsular biosynthesis genes, carbonic anhydrase, and an iron-uptake system while adhesion-linked variation was in pilC2 , marR, and mutS . Multiple phase variation states or combinatorial phasotypes were associated with significant differences in multiple phenotypes. Controlling for group effects through regression and recursive random forest approaches detected group-independent effects for nalP with biofilm formation and fetA with a growth trait. Through random forest testing, nine phenotypes were weakly predictive of MenW:cc11 sub-lineage, original or 2013, for disease isolates while three characteristics separated carriage and disease isolates with >80% accuracy. This study demonstrates the power of combining high-throughput phenotypic testing of pathogenically relevant isolate collections with genomics for identifying genetic determinants of specific disease-relevant phenotypes and the pathobiology of microbial pathogens.IMPORTANCENext-generation sequencing technologies have led to the creation of extensive microbial genome sequence databases for several bacterial pathogens. Mining of these databases is now imperative for unlocking the maximum benefits of these resources. We describe a high-throughput methodology for detecting associations between phenotypic variation in multiple disease-relevant traits and a range of genetic determinants for Neisseria meningitidis , a major causative agent of meningitis and septicemia. Phenotypic variation in 11 disease-related traits was determined for 163 isolates of the hypervirulent ST-11 lineage and linked to specific single-nucleotide polymorphisms, short sequence variants, and phase variation states. Application of machine learning algorithms to our data outputs identified combinatorial phenotypic traits and genetic variants predictive of a disease association. This approach overcomes the limitations of generic meta-data, such as disease versus carriage, and provides an avenue to explore the multi-faceted nature of bacterial disease, carriage, and transmissibility traits.

Objective: To compare immunological responses of preterm infants to a four-component meningococcal B vaccine (4CMenB; Bexsero) following a 2+1 vs a 3+1 schedule, and to describe reactogenicity of routine vaccines., Design: An open-label, phase IV randomised study conducted across six UK sites., Setting: Neonatal units, postnatal wards, community recruitment following discharge., Participants: 129 preterm infants born at a gestation of <35 weeks (64 in group 1 (2+1), 65 in group 2 (3+1)) were included in the analysis. Analysis was completed for postprimary samples from 125 participants (59 in group 1, 66 in group 2) and for postbooster samples from 118 participants (59 in both groups)., Interventions: Infants randomised to 4CMenB according to a 2+1 or a 3+1 schedule, alongside routine vaccines., Main Outcome Measures: Serum bactericidal antibody (SBA) assays performed at 5, 12 and 13 months of age: geometric mean titres (GMTs) and proportions of infants achieving titres ≥4 compared between groups., Results: There were no significant differences in SBA GMTs between infants receiving a 2+1 compared with a 3+1 schedule following primary or booster vaccination, but a significantly higher proportion of infants had an SBA titre ≥4 against strain NZ98/254 (porin A) at 1 month after primary vaccination using a 3+1 compared with a 2+1 schedule (3+1: 87% (95% CI 76 to 94%), 2+1: 70% (95% CI 56 to 81%), p=0.03).At 12 weeks of age those in the 3+1 group, who received a dose of 4CMenB, had significantly more episodes of fever >38.0°C than those in the 2+1 group who did not (group 2+1: 2% (n=1); 3+1: 14% (n=9); p=0.02)., Conclusions: Both schedules were immunogenic in preterm infants, although a lower response against strain NZ98/254 was seen in the 2+1 schedule; ongoing disease surveillance is important in understanding the clinical significance of this difference., Trial Registration Number: NCT03125616., Competing Interests: Competing interests: JL and RB perform contract research on behalf of UKHSA for GlaxoSmithKline (GSK), Pfizer and Sanofi. JC works for an institution which conducts meningococcal vaccine research on behalf of GSK; he receives no personal payment or inducement of any kind. MS was an employee of the University of Oxford and Oxford University Hospitals Foundation NHS trust up until September 2022, and in this role acted as an investigator for clinical research studies funded or otherwise supported by the vaccine manufacturers GSK, Janssen, AstraZeneca, Pfizer, Novavax and MCM vaccines. He received no personal financial benefit for this work. As of September 2022, MS has been an employee of Moderna UK and holds equity in this company; however, all study activities and data analysis were completed before this date., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

The meningococcal group B vaccine, 4CMenB, is a broad-spectrum, recombinant protein vaccine that is licensed for protection against meningococcal group B disease in children and adults. Over the past decade, several observational studies supported by laboratory studies have reported protection by 4CMenB against gonorrhoea, a sexually transmitted infection caused by Neisseria gonorrhoeae. Gonorrhoea is a major global public health problem, with rising numbers of diagnoses and increasing resistance to multiple antibiotics. In England, more than 82 000 cases of gonorrhoea were diagnosed in 2022, with nearly half of the cases diagnosed among gay, bisexual, and other men who have sex with men. There are currently no licensed vaccines against gonorrhoea but 4CMenB is estimated to provide 33-47% protection against gonorrhoea. On Nov 10, 2023, the UK Joint Scientific Committee on Vaccination and Immunisation agreed that a targeted programme should be initiated using 4CMenB to prevent gonorrhoea among individuals at higher risk of infection attending sexual health services in the UK. This decision was made after reviewing evidence from retrospective and prospective observational studies, laboratory and clinical data, national surveillance reports, and health economic analyses. In this Review, we summarise the epidemiology of invasive meningococcal disease and gonorrhoea in England, the evidence supporting the use of 4CMenB for protection against gonorrhoea, and the data needed to inform long-term programme planning and extension to the wider population., Competing Interests: Declaration of interests PJW has received payment from Pfizer for teaching of mathematical modelling of infectious disease transmission and vaccination. RB performs contract serology on behalf of UKHSA for GlaxoSmithKline, Pfizer, and Sanofi but receives no personal remuneration. SNL performs contract research for St George's University of London for vaccine manufacturers but receives no personal remuneration. All other authors declare no competing interests., (Crown Copyright © 2024 Published by Elsevier Ltd. All rights reserved.)

Invasive meningococcal disease (IMD), caused by infection with the bacterium Neisseria meningitidis, usually manifests as meningitis or septicemia and can be severe and life-threatening (1). Six serogroups (A, B, C, W, X, and Y) account for most cases (2). N. meningitidis is transmitted person-to-person via respiratory droplets and oropharyngeal secretions. Asymptomatic persons can carry N. meningitidis and transmit the bacteria to others, potentially causing illness among susceptible persons. Outbreaks can occur in conjunction with large gatherings (3,4). Vaccines are available to prevent meningococcal disease. Antibiotic prophylaxis for close contacts of infected persons is critical to preventing secondary cases (2)., Competing Interests: All authors have completed and submitted the International Committee of Medical Journal Editors form for disclosure of potential conflicts of interest. Jay Lucidarme, Stephen A. Clark, and Ray Borrow report performing contract research on behalf of the UK Health Security Agency (UKHSA) for GSK, Pfizer, and Sanofi. Muhamed-Kheir Taha reports performing contract research on behalf of the Institut Pasteur for GSK, Pfizer, and Sanofi. Shamez N. Ladhani reports performing contract research on behalf of the UKHSA and St. George’s University of London for GSK, Pfizer, Merck Sharp & Dohme, and Sanofi. Helen Campbell and Mary Ramsay report receipt of a recovery charge by the Immunisation and Vaccine Preventable Diseases Division at UKHSA for provision to vaccine manufacturers (GSK, Pfizer, and Sanofi) of postmarketing surveillance reports on meningococcal, Haemophilus influenzae, and pneumococcal infections, which are required by the U.K. Licensing Authority in compliance with their risk management strategy. Jennifer Zipprich reports that her spouse is employed by Pfizer. No other potential conflicts of interest were disclosed.

Guidelines for the prevention and treatment of infection in patients with an absent or dysfunctional spleen were published by the British Committee for Standards in Haematology in 1996 and updated in 2002 and 2011. With advances in vaccinations and changes in patterns of infection, the guidelines required updating. Key aspects included in this guideline are the identification of patients at risk of infection, patient education and information and immunisation schedules. This guideline does not address the non-infective complications of splenectomy or functional hyposplenism (FH). This replaces previous guidelines and significantly revises the recommendations related to immunisation. Patients at risk include those who have undergone surgical removal of the spleen, including partial splenectomy and splenic embolisation, and those with medical conditions that predispose to FH. Immunisations should include those against Streptococcus pneumoniae (pneumococcus), Neisseria meningitidis (meningococcus) and influenza. Haemophilus influenzae type b (Hib) is part of the infant immunisation schedule and is no longer required for older hyposplenic patients. Treatment of suspected or proven infections should be based on local protocols and consider relevant anti-microbial resistance patterns. The education of patients and their medical practitioners is essential, particularly in relation to the risk of serious infection and its prevention. Further research is required to establish the effectiveness of vaccinations in hyposplenic patients; infective episodes should be regularly audited. There is no single group ideally placed to conduct audits into complications arising from hyposplenism, highlighting a need for a national registry, as has proved very successful in Australia or alternatively, the establishment of appropriate multidisciplinary networks., (© 2024 British Society for Haematology and John Wiley & Sons Ltd.)

Background: Prepandemic sentinel surveillance focused on improved management of winter pressures, with influenza-like illness (ILI) being the key clinical indicator. The World Health Organization (WHO) global standards for influenza surveillance include monitoring acute respiratory infection (ARI) and ILI. The WHO's mosaic framework recommends that the surveillance strategies of countries include the virological monitoring of respiratory viruses with pandemic potential such as influenza. The Oxford-Royal College of General Practitioner Research and Surveillance Centre (RSC) in collaboration with the UK Health Security Agency (UKHSA) has provided sentinel surveillance since 1967, including virology since 1993., Objective: We aim to describe the RSC's plans for sentinel surveillance in the 2023-2024 season and evaluate these plans against the WHO mosaic framework., Methods: Our approach, which includes patient and public involvement, contributes to surveillance objectives across all 3 domains of the mosaic framework. We will generate an ARI phenotype to enable reporting of this indicator in addition to ILI. These data will support UKHSA's sentinel surveillance, including vaccine effectiveness and burden of disease studies. The panel of virology tests analyzed in UKHSA's reference laboratory will remain unchanged, with additional plans for point-of-care testing, pneumococcus testing, and asymptomatic screening. Our sampling framework for serological surveillance will provide greater representativeness and more samples from younger people. We will create a biomedical resource that enables linkage between clinical data held in the RSC and virology data, including sequencing data, held by the UKHSA. We describe the governance framework for the RSC., Results: We are co-designing our communication about data sharing and sampling, contextualized by the mosaic framework, with national and general practice patient and public involvement groups. We present our ARI digital phenotype and the key data RSC network members are requested to include in computerized medical records. We will share data with the UKHSA to report vaccine effectiveness for COVID-19 and influenza, assess the disease burden of respiratory syncytial virus, and perform syndromic surveillance. Virological surveillance will include COVID-19, influenza, respiratory syncytial virus, and other common respiratory viruses. We plan to pilot point-of-care testing for group A streptococcus, urine tests for pneumococcus, and asymptomatic testing. We will integrate test requests and results with the laboratory-computerized medical record system. A biomedical resource will enable research linking clinical data to virology data. The legal basis for the RSC's pseudonymized data extract is The Health Service (Control of Patient Information) Regulations 2002, and all nonsurveillance uses require research ethics approval., Conclusions: The RSC extended its surveillance activities to meet more but not all of the mosaic framework's objectives. We have introduced an ARI indicator. We seek to expand our surveillance scope and could do more around transmissibility and the benefits and risks of nonvaccine therapies., (©Xinchun Gu, Conall Watson, Utkarsh Agrawal, Heather Whitaker, William H. Elson, Sneha Anand, Ray Borrow, Anna Buckingham, Elizabeth Button, Lottie Curtis, Dominic Dunn, Alex J. Elliot, Filipa Ferreira, Rosalind Goudie, Uy Hoang, Katja Hoschler, Gavin Jamie, Debasish Kar, Beatrix Kele, Meredith Leston, Ezra Linley, Jack Macartney, Gemma L Marsden, Cecilia Okusi, Omid Parvizi, Catherine Quinot, Praveen Sebastianpillai, Vanashree Sexton, Gillian Smith, Timea Suli, Nicholas P B Thomas, Catherine Thompson, Daniel Todkill, Rashmi Wimalaratna, Matthew Inada-Kim, Nick Andrews, Victoria Tzortziou-Brown, Rachel Byford, Maria Zambon, Jamie Lopez-Bernal, Simon de Lusignan. Originally published in JMIR Public Health and Surveillance (https://publichealth.jmir.org), 03.04.2024.)

Background: People living with HIV have an increased risk of meningococcal disease. The Propositive trial evaluated co-administration of two doses of a four-component recombinant protein-based MenB vaccine (4CMenB) and a quadrivalent conjugate polysaccharide MenACWY vaccine (MenACWY-CRM197) given 1 month apart in people with HIV. The follow-up trial assessed the immunogenicity of these vaccines at 1.5 and 2.5 years after primary vaccination., Methods: Participants who completed the parent Propositive trial were invited to the follow-up study. Immunogenicity analysis was performed at 18 and 30 months after primary vaccination. Primary outcome measures were serum bactericidal antibody (SBA) geometric mean titres (GMTs) against three MenB reference strains and the proportion of participants maintaining a protective SBA titre of ≥4 at 18 and 30 months. Secondary outcome measures were SBA GMTs against MenA, C, W, and Y serogroups and the proportion of participants maintaining a protective SBA titre of ≥8 at 18 and 30 months. The trial is registered with Clinicaltrials.gov (NCT042394300)., Results: A total of 40 participants aged 22-47 years were enrolled. Geometric mean titres waned by 18 and 30 months but remained higher than pre-vaccination for all MenB strains and MenA, C, W, and Y. In total, 75%-85% of participants retained protective SBA titres by 30 months against individual MenB strains, whereas 68.8% of patients retained protective antibody titres against all three MenB strains. Antibodies against MenC waned more rapidly than did those against MenA, W, and Y. The proportion of participants with protective titres against MenC at 30 months was also lower (46.9%) than that with protective titres against MenA (87.5%), W (78.1%), and Y (87.5%)., Conclusions: Immune responses against MenB in our cohort of people living with HIV at 2.5 years of follow-up were reassuring, with 68.8% of participants retaining protection against all three reference strains. However, responses against MenC were lower than those against MenA, W, and Y serogroups., (© 2023 The Authors. HIV Medicine published by John Wiley & Sons Ltd on behalf of British HIV Association.)

Introduction: Outer membrane vesicles (OMVs) of Neisseria meningitidis in the group B-directed vaccine MenB-4C (Bexsero R ) protect against infections with Neisseria gonorrhoeae . The immunological basis for protection remains unclear. N. meningitidis OMV vaccines generate human antibodies to N. meningitidis and N. gonorrhoeae lipooligosaccharide (LOS/endotoxin), but the structural specificity of these LOS antibodies is not defined., Methods: Ten paired human sera obtained pre- and post-MenB-4C immunization were used in Western blots to probe N. meningitidis and N. gonorrhoeae LOS. Post-MenB-4C sera (7v5, 19v5, and 17v5), representing individual human variability in LOS recognition, were then used to interrogate structurally defined LOSs of N. meningitidis and N. gonorrhoeae strains and mutants and studied in bactericidal assays., Results and Discussion: Post-MenB-4C sera recognized both N. meningitidis and N. gonorrhoeae LOS species, ~10% of total IgG to gonococcal OMV antigens. N. meningitidis and N. gonorrhoeae LOSs were broadly recognized by post-IgG antibodies, but with individual variability for LOS structures. Deep truncation of LOS, specifically a rfa K mutant without α -, β -, or γ -chain glycosylation, eliminated LOS recognition by all post-vaccine sera. Serum 7v5 IgG antibodies recognized the unsialyated L1 α -chain, and a 3-PEA-HepII or 6-PEA-HepII was part of the conformational epitope. Replacing the 3-PEA on HepII with a 3-Glc blocked 7v5 IgG antibody recognition of N. meningitidis and N. gonorrhoeae LOSs. Serum 19v5 recognized lactoneotetrose (LNT) or L1 LOS-expressing N. meningitidis or N. gonorrhoeae with a minimal α -chain structure of Gal-Glc-HepI (L8), a 3-PEA-HepII or 6-PEA-HepII was again part of the conformational epitope and a 3-Glc-HepII blocked 19v5 antibody binding. Serum 17v5 LOS antibodies recognized LNT or L1 α -chains with a minimal HepI structure of three sugars and no requirement for HepII modifications. These LOS antibodies contributed to the serum bactericidal activity against N. gonorrhoeae . The MenB-4C vaccination elicits bactericidal IgG antibodies to N. gonorrhoeae conformational epitopes involving HepI and HepII glycosylated LOS structures shared between N. meningitidis and N. gonorrhoeae. LOS structures should be considered in next-generation gonococcal vaccine design., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Tzeng, Sannigrahi, Borrow and Stephens.)

This review details recent findings from the Global Meningococcal Initiative's (GMI) recent meeting on the surveillance and control strategies for invasive meningococcal disease in the Middle East. The nature of case reporting and notification varies across the region, with many countries using bacterial meningitis as an IMD case definition in lieu of meningitis and septicaemia. This may overlook a significant burden associated with IMD leading to underreporting or misreporting of the disease. Based on these current definitions, IMD reported incidence remains low across the region, with historical outbreaks mainly occurring due to the Hajj and Umrah mass gatherings. The use of case confirmation techniques also varies in Middle Eastern countries. While typical microbiological techniques, such as culture and Gram staining, are widely used for characterisation, polymerase chain reaction (PCR) testing is utilised in a small number of countries. PCR testing may be inaccessible for several reasons including sample transportation, cost, or a lack of laboratory expertise. These barriers, not exclusive to PCR use, may impact surveillance systems more broadly. Another concern throughout the region is potentially widespread ciprofloxacin resistance since its use for chemoprophylaxis remains high in many countries., Competing Interests: Declaration of Competing Interest Xilian Bai performs contract research on behalf of UKHSA for GSK, PATH, Pfizer and Sanofi Pasteur. Ray Borrow performs contract research on behalf of UKHSA for GSK, PATH, Pfizer and Sanofi Pasteur. Ener Cagri Dinleyici performs contract work for the Eskisehir Osmangazi University funded by GSK, Sanofi Pasteur and Pfizer. Jay Lucidarme performs contract research on behalf of UKHSA for GSK, PATH, Pfizer and Sanofi Pasteur. Marco A. P. Sáfadi reports research grants and personal fees for advisory boards from GSK, Pfizer, and Sanofi. Vinny Smith and Claire Wright work for the MRF that receives grants and/or sponsorship from GSK, PATH, Pfizer, Sanofi, Bill and Melinda Gates Foundation, and Serum Institute of India. M.K. Taha performs contract work for the Institut Pasteur funded by GSK, Pfizer and Sanofi Pasteur. M.K. Taha and A.E. Deghmane has a patent NZ630133A Patent with GSK “Vaccines for serogroup X meningococcus” issued. J.A. Vázquez performs contract work for the Institute of Health Carlos III funded by GSK and Pfizer and he has received personal fees from Pfizer and Sanofi Pasteur., (Copyright © 2023. Published by Elsevier Ltd.)

Introduction: Rotavirus is a leading cause of severe diarrheal disease and death in children under five years of age worldwide. Vaccination is one of the most important public health interventions to reduce this significant burden., Areas Covered: This literature review examined vaccination coverage, hospitalization rate, mortality, genotypic distribution, immunogenicity, cost-effectiveness, and risk versus benefit of rotavirus vaccination in children in South America. Nine out of twelve countries in South America currently include a rotavirus vaccine in their national immunization program with coverage rates in 2022 above 90%., Expert Opinion: Introduction of the rotavirus vaccination has led to a marked reduction in hospitalizations and deaths from diarrheal diseases in children under 5 years, particularly infants under 1 year, in several South American countries. In Brazil, hospitalizations decreased by 59% and deaths by 21% (30-38% in infants). In Peru, hospitalizations in infants fell by 46% and deaths by 37% (56% in infants). Overall, data suggest that rotavirus vaccination has reduced rotavirus deaths by 15-50% in various South American countries. There is some evidence that immunity wanes after the age of 1-year old. Ongoing surveillance of vaccine coverage and changes in morbidity and mortality is important to maximize protection against this disease.

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.