INO-4800 is being developed by US-based Inovio Pharmaceuticals Inc. (INO).Current Status: INO-4800 is under a phase I trial in the U.S. and in phase I/II trial in South Korea. Preliminary results reported from the U.S trial on June 30, 2020, demonstrated an overall immune response rate of 94% at Week 6. Mode of Action: INO-4800 is a vaccine that contains DNA encoding for the SARS-CoV-2 spike protein, the major surface antigen of coronaviruses. Upon vaccination, the spike protein will be produced in the cells, triggering antigen-specific T cell responses and functional antibodies. When a vaccinated person is infected by SARS-CoV-2, the antigen-specific T cell responses and functional antibodies will neutralize the virus infection.Next Milestone:A phase II/III efficacy trial in the U.S. is expected to start this summer.