Gemini (Eyam Health)

Gemini is a bi-functional plasmid vector platform developed by Eyam Vaccines and Immunotherapeutics (Eyam Health) that can be delivered as either self-amplifying RNA (saRNA) or self-amplifying DNA (saDNA). Derived from alphavirus replicon technology, specifically the Venezuelan equine encephalitis (VEE) virus, the platform incorporates non-structural protein genes (NSP1-4) and a 26S sub-genomic promoter to drive high-level, sustained expression of genetic payloads. A key advantage of the Gemini system is its ability to be delivered without lipid nanoparticle (LNP) encapsulation, which, combined with its stability during lyophilization and ambient-temperature storage, simplifies logistics. The platform supports a large payload capacity of 16-20 kb and has been demonstrated to elicit robust antibody and T-cell responses in applications such as COVID-19 vaccines and cancer immunotherapies.