Summary
Antimicrobial resistance in Neisseria gonorrhoeae is a growing global threat, especially in LMICs, where limited resources hinder diagnosis and treatment. Resistance to key antibiotics like azithromycin and ceftriaxone jeopardizes current therapies. Untreated gonorrhoea can cause severe reproductive health issues and heighten HIV risk. Despite its impact, no commercial vaccine exists to prevent gonorrhoea infections. This proposal aims to develop an mRNA-LNP gonorrhoea vaccine using Afrigen’s mRNA platform. Through collaboration with Evaxion (Denmark) and their proprietary AI platform (EDENTM), four protective B-cell antigens from the Neisseria gonorrhoeae proteome were encoded into mRNA and encapsulated in lipid nanoparticles to produce four mRNA-LNP vaccine candidates. All four candidates were tested in mice, and showed strong immunogenicity and serum bactericidal activity, demonstrating a novel, promising approach to reducing antibiotic reliance.
Further to the mRNA vaccine candidate, a recombinant protein-based vaccine, EVX-B2 formulated with the adjuvant GLA-SE, was developed and demonstrated immunogenicity in the same mouse model. The proposal is to further undertake preclinical development of the down selected mRNA and protein vaccine candidates by demonstrating protective efficacy through a female mouse genital tract challenge model.
Dr Caryn Fenner
Director of mRNA Hub
Afrigen Biologics
South Africa
Collaborators:
Dr Sanjay Ram, Professor of Medicine, Umass Chan Medical School, USA
Dr Adam Ritchie, Senior Vaccinologist, Jenner Instititute, University of Oxford, UK