Therapeutic and prophylactic applications of self-replicating RNA viruses

Self-replicating RNA viruses have been commonly used for preventive and therapeutic interventions in the fields of infectious diseases and cancers. Both RNA viruses with single-stranded RNA genomes of positive and negative polarity have been utilized. Expression of viral surface proteins from self-replicating RNA virus vectors has elicited strong immune responses and provided protection against challenges with lethal doses of pathogens in various animal models using recombinant viral particles, RNA replicons, or plasmid-based replicon vectors. Similarly, immunization with self-replicating RNA virus vectors expressing tumor antigens has induced tumor-specific antibody (Ab) responses, inhibited tumor growth, eradicated tumors, and protected immunized animals against tumor challenges. Clinical trials have demonstrated good safety and tolerance of self-replicating RNA viruses. Although the number of clinical trials is low, robust immune responses and protection against challenges with pathogens and tumor cells have been achieved. The Ervebo vaccine against Ebola virus disease has been approved by both the European Medicines Agency (EMA) and the US Food and Drug Administration (FDA).