Replicon RNA (repRNA)

Replicon RNA (repRNA) is a synthetic, self-amplifying RNA engineered by deleting the structural genes of certain single-stranded RNA viruses (such as alphavirus, rhabdovirus, or flavivirus) and replacing them with genes encoding desired vaccine antigens or therapeutic proteins. The remaining non-structural genes encode an RNA-dependent RNA polymerase, which allows the RNA to self-replicate in the cytoplasm of transfected cells, massively amplifying the production of the encoded antigen and stimulating strong humoral and cellular immune responses. RepRNA cannot produce infectious virus progeny, making it a safe vaccine platform. Formulations for repRNA (including nanoparticles like LION) are essential for efficient delivery and for modulating the immune response. This technology has been used for vaccine development against a variety of infectious diseases and is viewed as a promising alternative to conventional mRNA vaccines, offering higher potency at lower doses and potentially broader applications.

Other names

Self-amplifying RNASelf-amplifying replicon RNAsaRNA

Used as a vehicle to deliver antigen-encoding genes into host cells. Undergoes self-replication via the preserved viral non-structural genes (e.g., alphavirus, flavivirus, or rhabdovirus replicase genes) to amplify mRNA, resulting in high levels of antigen production and robust immune stimulation