Poster Presentation Australian Society for Microbiology Annual Scientific Meeting 2024

Development of a bacterial mRNA vaccine against Streptococcus pyogenes using Moderna platform technology (#31)

Nichaela Harbison-Price 1 , Ismail Sebina 2 , Rhiannon A Bolton 2 , Meredith Finn 3 , Amanda J Cork 1 , Isabel G Courtney 2 , Johanna Richter 1 , Samantha Falcone 3 , Fabio Silva 3 , Christina Dold 3 , Laura Davis 1 , Brody Pullinger 1 , Gayathiri Elangovan 1 , Bodie F Curren 1 , Nia Bickham 1 , Ruby Pelingon 1 , Miguel Aguirre 1 , Stephan Brouwer 1 , Obadiah Plante 3 , Gabrielle T Belz 2 , Mark J Walker 1
  1. Centre for Superbug Solutions, Institute for Molecular Bioscience, The University of Queensland, Brisbane, Queensland, Australia
  2. Frazer Institute, The University of Queensland, Brisbane, Queensland, Australia
  3. Moderna TX, 200 Technology Square, Cambridge, Massachusetts, USA

A commercial vaccine to address the high global burden of disease caused by Group A Streptococcus (GAS) is an urgent and unmet need. Messenger RNA (mRNA) lipid-nanoparticle (LNP) vaccines represent a largely untapped platform for targeting bacterial pathogens that may overcome technological and economic challenges impeding conventional vaccine platforms for large-scale manufacture and global accessibility. Here, we evaluated the immunogenicity and preclinical efficacy of a Moderna mRNA-LNP vaccine formulation based on the non-M-protein based GAS vaccine candidate, Combo#5. In this study we demonstrate mRNA-LNP constructs of individual Combo#5 antigens (SCPA, SLO, TF, ADI, and SpyCEP) expressed as either soluble or transmembrane-anchored (TM) proteins elicited strong antigen-specific IgG1, IgG2a, IgG2b and IgG3 responses in BALB/c mice, indicative of a Th1/Th2-type response. A multicomponent Combo#5 mRNA-LNP formulation of all TM constructs (Combo#5-TM) conferred protection to BALB/c and humanized plasminogen (hPLG) mice against invasive intraperitoneal and subcutaneous infection, respectively. A multicomponent Combo#5 mRNA-LNP formulation of all soluble constructs (Combo#5-soluble) only provided protection in the BALB/c intraperitoneal challenge mouse model. These findings demonstrate the utility of the Moderna mRNA vaccine platform for the development of vaccines against bacterial pathogens.