Abstract
Although virus-like particle (VLP) vaccines were shown to be effective against several viruses, their advantage over vaccines that include envelope protein only is not completely clear, particularly for mRNA-encoded VLPs. We conducted a side-by-side comparison of the immunogenicity and protective efficacy of mRNA vaccines encoding the Marburg virus (MARV) full-length glycoprotein (GP) delivered alone or as a VLP. Electron microscopy confirmed VLP formation when MARV GP and matrix protein VP40 were coexpressed. We vaccinated guinea pigs with a 2-component mRNA vaccine encoding GP and VP40 (VLP) or GP alone. At the highest dose, both vaccines protected fully, although the VLP vaccine elicited a slightly lower humoral response than did the GP-only mRNA vaccine. However, at low doses, GP-only mRNA conferred 100% protection, whereas the VLP vaccine conferred only partial protection. In mice, VLP mRNA induced a moderate preference for GP-specific CD8+ T cell responses, whereas the GP-only mRNA somewhat favored CD4+ T cell responses. Guinea pig whole-blood RNA-Seq revealed that the VLP vaccine downregulated genes associated with various biological and metabolic processes, including the NF-κB signaling pathway, whereas the GP-only vaccine upregulated IFN signaling. Overall, the VLP mRNA vaccine was less immunogenic and protective, whereas the GP-only mRNA vaccine conferred robust protection with a dose of as little as 1 μg in guinea pigs.
Authors
Chandru Subramani, Michelle Meyer, Matthew A. Hyde, Margaret E. Comeaux, Haiping Hao, James E. Crowe Jr., Vsevolod L. Popov, Harshwardhan Thaker, Sunny Himansu, Andrea Carfi, Alexander Bukreyev
Figure 7
Assessment of MARV GP and VLP mRNA vaccines in guinea pig study 2: protective efficacy.
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)