Characterization of vaccine antigens of meningococcal serogroup W isolates from Ghana and Burkina Faso from 2003 to 2009

Emma Ispasanie; Gerd Pluschke; Abraham Hodgson; Ali Sie; Calman MacLennan; Oliver Koeberling

doi:10.12688/f1000research.3881.1

Characterization of vaccine antigens of meningococcal serogroup W isolates from Ghana and Burkina Faso from 2003 to 2009

F1000Res. 2014 Nov 3:3:264. doi: 10.12688/f1000research.3881.1. eCollection 2014.

Authors

Emma Ispasanie¹, Gerd Pluschke², Abraham Hodgson³, Ali Sie⁴, Calman MacLennan⁵, Oliver Koeberling⁶

Affiliations

¹ Novartis Vaccines Institute for Global Health, 53100, Siena, Italy ; MRC Centre for Immune Regulation, School of Immunity and Infection, College of Medicine and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK ; Molecular Immunology Department, Swiss Tropical and Public Health Institute, Basel, 4002, Switzerland.
² Molecular Immunology Department, Swiss Tropical and Public Health Institute, Basel, 4002, Switzerland ; University of Basel, Basel, 4003, Switzerland.
³ Navrongo Health Research Centre, Navrongo, PO Box 114, Ghana.
⁴ Centre de Recherche en Santé de Nouna, PO Box 02, Nouna, Burkina Faso.
⁵ Novartis Vaccines Institute for Global Health, 53100, Siena, Italy ; MRC Centre for Immune Regulation, School of Immunity and Infection, College of Medicine and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK.
⁶ Novartis Vaccines Institute for Global Health, 53100, Siena, Italy.

Abstract

Neisseria meningitidis is a major cause of bacterial meningitis and a considerable health problem in the 25 countries of the 'African Meningitis Belt' that extends from Senegal in West Africa to Ethiopia in the East. Approximately 80% of cases of meningococcal meningitis in Africa have been caused by strains belonging to capsular serogroup A. After the introduction of a serogroup A conjugate polysaccharide vaccine, MenAfriVac (™), that began in December 2010, the incidence of meningitis due to serogroup A has markedly declined in this region. Currently, serogroup W of N. meningitidis accounts for the majority of cases. Vaccines based on sub-capsular antigens, such as Generalized Modules for Membrane Antigens (GMMA), are under investigation for use in Africa. To analyse the antigenic properties of a serogroup W wave of colonisation and disease, we investigated the molecular diversity of the protein vaccine antigens PorA, Neisserial Adhesin A (NadA), Neisserial heparin-binding antigen (NHBA) and factor H binding protein (fHbp) of 31 invasive and carriage serogroup W isolates collected as part of a longitudinal study from Ghana and Burkina Faso between 2003 and 2009. We found that the isolates all expressed fHbp variant 2 ID 22 or 23, differing from each other by only one amino acid, and a single PorA subtype of P1.5,2. Of the isolates, 49% had a functional nhbA gene and 100% had the nadA allele 3, which contained the insertion sequence IS1301 in five isolates. Of the W isolates tested, 41% had high fHbp expression when compared with a reference serogroup B strain, known to be a high expresser of fHbp variant 2. Our results indicate that in this collection of serogroup W isolates, there is limited antigenic diversification over time of vaccine candidate outer membrane proteins (OMP), thus making them promising candidates for inclusion in a protein-based vaccine against meningococcal meningitis for Africa.

Keywords: Neisseria meningitidis; meningococcus; meningitis; serogroup W; factor H binding protein; NadA, NHBA.

Grants and funding

This work was supported by an EU FP7 Marie Curie Actions Industry Academia Partnerships and Pathways (IAPP) Consortium Programme, entitled GENDRIVAX (Genome-driven vaccine development for bacterial infections).