Serogroup A meningococcal conjugate vaccines: building sustainable and equitable vaccine strategies

Abstract

Introduction: For well over 100 years, meningococcal disease due to serogroup A Neisseria meningitidis (MenA) has caused severe epidemics globally, especially in the meningitis belt of sub-Saharan Africa.

Areas covered: The article reviews the background and identification of MenA, the global and molecular epidemiology of MenA, and the outbreaks of MenA in the African meningitis belt. The implementation (2010) of an equitable MenA polysaccharide-protein conjugate vaccine (PsA-TT, MenAfriVac) and the strategy to control MenA in sub-Saharan Africa is described. The development of a novel multi-serogroup meningococcal conjugate vaccine (NmCV-5) that includes serogroup A is highlighted. The PubMed database (1996-2019) was searched for studies relating to MenA outbreaks, vaccine, and immunization strategies; and the Neisseria PubMLST database of 1755 MenA isolates (1915-2019) was reviewed.

Expert opinion: Using strategies from the successful MenAfriVac campaign, expanded collaborative partnerships were built to develop a novel, low-cost multivalent component meningococcal vaccine that includes MenA. This vaccine promises greater sustainability and is directed toward global control of meningococcal disease in the African meningitidis belt and beyond. The new WHO global roadmap addresses the continuing problem of bacterial meningitis, including meningococcal vaccine prevention, and provides a framework for further reducing the devastation of MenA.

Keywords: Neisseria meningitidis; conjugate vaccine; immunization strategies; serogroup A.

Figure 1.

Global epidemiology of meningococcal disease by serogroup, including serogroup A. Meningococcal serogroups are listed in the order of the estimated incidence (2010–2019) causing disease; however, in some areas, (*) data are quite limited. Serogroups are linked to 12 major genetic clonal complexes currently causing almost invasive meningococcal disease (modified from Stephens, DS, Neisseria meningitidis in Mandell, Douglas, Bennett Principles & Practices of Infectious Diseases, Bennett, Dolin, Blaser, eds.).

Figure 2.

The meningitis belt of sub-Saharan Africa, from Meningococcal Disease, Chapter 4–2018 Yellow Book Centers for Disease Control and Prevention. Disease data source: World Health Organization. International Travel and Health. Geneva, Switzerland: 2012.

Figure 3.

A summary of the meningitis task force goals and timeline, with a focus on Nm.