Phase II / III Study of COVID-19 DNA Vaccine (AG0302-COVID19)

This is a Phase II /III, multi-center, randomized, double-blind, placebo controlled trial. Approximately 500 healthy volunteers, male or female, aged 18 years or older, will be randomized to one of the following two groups:

Group A: Vaccination twice at 2-week intervals (n = 250) Group B: Vaccination twice at 4-week intervals (n = 250)

Fifty subjects in each group will receive placebos.

Inclusion criteria

• Subjects who have obtained written consent voluntarily to participate in this clinical trial
• Subjects whose age at the time of obtaining consent is 18 years or older
• Subjects who are negative for SARS-CoV-2 by PCR test
• Subjects who are negative for both SARS-CoV-2 IgM antibody and SARS-CoV-2 IgG antibody by antibody test

Exclusion criteria

• Subjects with symptoms of suspected COVID-19 infection (respiratory symptoms, headache, malaise, olfactory disorders, taste disorders, etc.)
• Subjects with a history of COVID-19 (hearing from subjects)
• Subjects who have participated in unapproved vaccine clinical trials within 1 year before the start of this study
• Subjects with axillary temperature of 37.0 degree or higher at the time of screening and before the first vaccination
• Subjects who have a history of anaphylaxis
• Subjects who have a history of hypersensitivity to the ingredients of the investigational drug
• Subjects who have a current or history of serious renal, cardiovascular, respiratory, liver, kidney, gastrointestinal, and neuropsychiatric diseases
• Subjects with a history of convulsion or epilepsy
• Subjects with a history of diagnosis of immunodeficiency
• Subjects who have a close relative (within 3rd degree) of congenital immunodeficiency
• Subjects who have current bronchial asthma
• Subjects who have had a fever of 39.0 degrees or higher within 2 days after vaccination, or who have been suspected of having an allergy such as a systemic rash.
• Females who wish to become pregnant from the study registration to 12 weeks after the first vaccination, and pregnant females who are breast-feeding. In addition, females who may become pregnant and their male sexual partners should use appropriate contraceptives (pill), condoms, vasectomy, tubal ligation, diaphragm, intrauterine devices, spermicides, intrauterine hormone-releasing system, etc. from the study entry date until 12 weeks after the first vaccination
• Subjects who have participated in clinical trials of other unapproved drugs and received the investigational drug within 4 weeks before the start of this clinical trial (starting from vaccination day)
• Subjects who have been received a live vaccine, inactivated vaccine, or toxoid within 4 weeks before the start of this clinical trial (starting from vaccination day)
• Subjects who have been administered with drugs that affect the immune system (excluding external preparations) such as immunomodulators (DMARDs, etc.), immunosuppressants, biologics, etc. within 4 weeks before vaccination
• Subjects who received blood transfusion or gamma globulin therapy within 12 weeks before vaccination, or high-dose gamma globulin therapy (200 mg/kg or more) within 24 weeks before vaccination
• Subjects who have a history of overseas travel within 4 weeks before the start of the clinical trial (starting from vaccination day)
• Subjects who are unable to comply with the clinical trial protocol and follow up (for mental, family, social or geographical reasons)
• Subjects who are judged to be ineligible for this clinical trial by the investigator