Evaluating Safety, Tolerability, and Potential Efficacy of Intranasal AD17002 in Adults With Mild to Moderate COVID-19

Inclusion Criteria: 1. Aged ≥ 20 and ≤ 70 years 2. SARS-CoV-2 infection confirmed by real-time RT-PCR ≤ 4 days before randomization. 3. Symptoms of mild to moderate illness with COVID-19 at Screening. At least one key COVID-19 symptom should have a score of 2 or higher using the scoring system in the diary card, with the exception of fever, sense of smell, and sense of taste where participants may be enrolled with a score of 1 or higher. 4. Have a negative serum pregnancy test at Screening (for female participants of childbearing potential). A female participant who is of childbearing potential agrees to remain abstinent or use (or have their partner use) two acceptable methods of birth control within the projected duration of the study. Acceptable methods of birth control are: intrauterine device, hormonal contraception, diaphragm with spermicide, contraceptive sponge, condom, vasectomy, as per local regulations or guidelines. 5. Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) ≤ 2.5-fold of upper limit of normal (ULN) and total bilirubin ≤ 1.5-fold of ULN. 6. Creatinine clearance ≥ 50 mL/min. 7. A female participant who is not of childbearing potential is eligible without requiring the use of contraception. A female participant who is not of childbearing potential is defined as one who has either: 1. Reached natural menopause (defined as 6 months of spontaneous amenorrhea with serum follicle-stimulating hormone levels in the postmenopausal range as determined by the laboratory, or 12 months of spontaneous amenorrhea), or 2. At least six weeks postsurgical documented total hysterectomy and/or bilateral salpingo-oophorectomy, or 3. Bilateral tubal ligation 8. Participant or the participant's legal representative understands the study procedures, alternative treatments available, risks involved with the study, and voluntarily agrees to participate by giving written informed consent. 9. Provide written informed consent for the study and willing to adhere to dose regimen and visit schedules. Exclusion Criteria: 1. Participant has clinical signs suggestive of moderate (pneumonia) or more severe illnesses with COVID-19 (as defined in the Taiwan CDC "Interim Guideline for Clinical Management of SARS-CoV-2 Infection Version 13" (Taiwan CDC, Clinical Management of SARS-CoV-2 Infection). 2. Participation in any other clinical study of an investigational agent treatment for SARS- CoV-2 infection within 30 days prior to the first IMP dosing. 3. Participant who has a history of confirmed SARS-CoV-2 infection. 4. Concurrent treatment with other agents with actual or possible direct acting antiviral activity against SARS-CoV-2 \< 24 hours prior to the first IMP dosing. 5. History of severe renal disease (treatment with dialysis or phosphate binders) or clinically apparent hepatic impairment (e.g., jaundice, cholestasis, hepatic synthetic impairment, active hepatitis). 6. Impaired cardiac function or clinically significant cardiac diseases as judged by the Investigator. 7. History of anaphylaxis reaction to any known or unknown cause. 8. Immunosuppressed persons as result of illness (e.g., HIV infection) or treatment. 9. Documented history of Bell's palsy. 10. History of allergic reaction to kanamycin. 11. Immunosuppressive treatment within 3 months prior to the Screening Visit. 12. Ongoing treatment with any specific immunotherapy at the time of the Screening Visit. 13. Assessed by the Investigator to be ineligible to participate in the study.