The important lessons lurking in the history of meningococcal epidemiology

ABSTRACT

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.

KEYWORDS:

• Epidemiology
• meningococcal disease
• meningococcal vaccines
• Neisseria meningitidis
• outbreaks

Article highlights

• Basic microbiologic characteristics of Neisseria meningitidis, including structural features and genomic plasticity, yield important influence on meningococcal virulence, and, in turn, epidemiology and vaccine development.

• Comprehensive and open-access meningococcal classification data, which generally rely on continually evolving immunologic or molecular methods, are crucial for global meningococcal surveillance.

• Currently available, demonstrably effective vaccines against invasive meningococcal disease (IMD) include polysaccharide vaccines for serogroups A, C, W, and Y and subcapsular protein vaccines for serogroup B, with a first-in-class pentavalent MenABCWY vaccine licensed in the United States in October 2023.

• Historical and contemporary data highlight that serogroups A, B, C, W, and Y have consistently caused the vast majority of IMD, with serogroup X limited to occasional outbreaks in Africa and sporadic cases elsewhere.

• Meningococcal epidemiology is also characterized by dynamic evolution of hyperinvasive clones and affected regions, with recent concerns including the global rise in serogroup W disease, increases in the prevalence of meningococcal antimicrobial resistance (AMR) and urethritis, and IMD rebounds among unvaccinated populations following lifting of COVID-19 restrictions.

• Despite these everchanging developments, future IMD surges are likely to conform with established trends of major disease-causing serogroups and affected age groups (infants and young children, adolescents/young adults, and the elderly).

• In addition to playing a key role in the fight against AMR, expanding meningococcal vaccination programs to include vaccination against all 5 major serogroups and in all risk-based age groups thus represents a key strategy in pursuit of the World Health Organization's goal of defeating meningitis by the year 2030.

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Declaration of interest

R Borrow performs contract research on behalf of the UK Health Security Agency for GSK, Pfizer, and Sanofi Pasteur. J Findlow is an employee of Pfizer and may hold stock or stock options. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or material discussed in the manuscript apart from those disclosed.

Reviewer disclosures

A reviewer on this manuscript has disclosed that they have worked on a meningococcal vaccine project which was funded by the Serum Institute of India awarded to current supervisor, not themselves. Peer reviewers on this manuscript have no other relevant financial or other relationships to disclose.

Author contributions

Both authors substantially contributed to the conception and design of the review article, interpretation of the relevant literature, and writing of the article or revising it for intellectual content.

Acknowledgments

Editorial/medical writing support was provided by Judith Kandel, PhD, Andrea Bothwell, BSc, Tricia Newell, PhD, and Sheena Hunt, PhD (all of ICON; Blue Bell, PA, USA) and was funded by Pfizer Inc.

Additional information

Funding

This work was supported by Pfizer Inc.