SW-0123

**SW-0123** is an mRNA-based COVID-19 vaccine developed by Stemirna Therapeutics, featuring sequence-optimized mRNA encoding the full-length SARS-CoV-2 spike protein encapsulated in core-shell structured lipopolyplex (LPP) nanoparticles for enhanced stability, uptake, and biodistribution with minimal liver accumulation. It elicits robust Th1-polarized immune responses, including high-titer neutralizing antibodies against wild-type SARS-CoV-2 and variants like D614G and N501Y, as well as strong CD4+ and CD8+ T cell responses producing IFN-γ, IL-2, and TNF-α. Preclinical studies in mice and nonhuman primates demonstrated dose-dependent immunogenicity, broad variant protection, and significant reduction in viral load and lung pathology upon challenge, with a favorable safety profile showing only mild injection-site reactogenicity.