Immunogenicity and Safety Study of SARS-CoV-2 DNA Vaccine (ICCOV)

This is an open-labeled, no placebo, Phase IIa clinical trial to evaluate the immunogenicity and safety of one booster vaccine dose of SARS-CoV-2 DNA Vaccine (ICCOV) in adults aged 18 to 75 years who have received two to four dosese of COVID-19 vaccine. The primary purpose of this study is to evaluate cross-reactive T cell responses against SARS-CoV-2 prototype and epidemic variants induced by one booster dose of ICCOV. The secondary purposes are 1) to evaluate other variables of cross-reactive T cell responses against SARS-CoV-2 prototype and epidemic variants induced by one booster dose of ICCOV; 2) to evaluate humoral immunity responses against SARS-CoV-2 prototype and epidemic variants induced by one boosterdose of ICCOV; and 3) to evaluate the safety and reactogenicity of ICCOV.