HDT Bio is a Seattle-based, clinical-stage biopharmaceutical development company. With core technology and expertise in nucleic acid formulation, the company develops products that seek to harness host-directed immune responses. HDT Bio’s work focuses on infectious disease and oncology vaccines and therapeutics through early-stage collaborations with partners worldwide. The company’s vaccine platform, repRNA/LION™, combines formulation and adjuvant ingredients to stabilize and deliver self-amplifying RNA to the immune system to stimulate responses. HDT Bio’s COVID-19 vaccine is the first self-amplifying RNA vaccine to ever receive a regulatory authorization.