We have try to develop the novel therapeutic vaccines for chronic diseases for these ten years. To fight against the worldwide COVID-19 pandemic, we also designed plasmid DNA vaccine targeting the SARS-CoV-2 Spike glycoprotein (S protein) as pandemic vaccine, and the humoral, cellular, and functional immune responses were characterized to support proceeding to initial human clinical trials. After intramuscular injection or intradermal injection with needleless injector of DNA vaccine encoding S protein (three times at 2-week intervals), the humoral immunoreaction, as assessed by anti-S protein or anti-receptor-binding domain (RBD) antibody titers, and the cellular immunoreaction, as assessed by antigen-induced IFNg expression, were up-regulated. We also confirmed the neutralizing action of DNA vaccine-induced antibodies. Further B cell epitope mapping analysis using a peptide array showed that most vaccine-induced antibodies recognized the S2 and RBD subunits. In conclusion, DNA vaccine targeting the spike glycoprotein of SARS-CoV-2 might be an effective and safe approach.