A Study to Evaluate the Safety and Immunogenicity of COVID-19 (AdimrSC-2f) Vaccine

Inclusion Criteria: * Subjects who meet ALL inclusion criteria will be included. 1. Male or non-pregnant female, aged 20 to 60 years old (inclusive). 2. Subject who is physically and mentally capable of participating the study and are willing to adhere to study procedures. 3. Subject with no clinically significant abnormal findings in medical history, physical examination, vital signs, or clinical laboratory results at the Screening visit based on the investigator's judgment. 4. Subject with negative test result in SARS-CoV-2 antibody (IgG and IgM) rapid test at the Screening visit. 5. Subject with negative serology test results for human immunodeficiency virus (HIV) antibody, hepatitis B surface antigen, and hepatitis C antibody at the Screening visit. 6. Subjects' clinical laboratory test results are in the normal range or with abnormal values without clinical significance as judged by the investigator. 7. Female subject with childbearing potential must have negative result in urine pregnancy test at the Screening visit. 8. Female subject with childbearing potential must be willing to implement adequate, highly effective contraceptive measure during the study period. Effective birth control includes: 1. Intrauterine device plus one barrier method 2. Oral, implantable, or injectable contraceptives plus one barrier method; or 3. Two barrier methods Effective barrier methods are male or female condoms, diaphragms, or spermicides (creams or gels that contain a chemical to kill sperm). Women of childbearing potential are those who have not been surgically sterilized or have not been free from menses for ≥ 1 year. 9. Male subject who agrees to use an adequate method of contraception during the study period \[e.g., barrier contraceptives (male condom)\]. 10. Subject who provides informed consent after receiving a detailed explanation of study procedures. Exclusion Criteria: * Subjects who meet ANY exclusion criteria will be excluded. 1. Subject with a body mass index (BMI) \< 18.5 kg/m2 (underweight) or ≥ 35 kg/m2 (greater than Class I obesity) at the Screening Visit. 2. Subject with history of cancer (except localized skin cancer without metastases) within 5 years prior to the Screening visit. 3. Subject has ongoing or medical history of hypertension or diabetes mellitus. 4. Subject has ongoing use of tobacco or nicotine-containing products (nicotine patch included) or e-cigarette devices or with history of using nicotine-containing product as documented in medical chart or by verbal confirmation at screening. 5. Subject with documented history of substance or alcohol abuse in the medical chart or by verbal confirmation within 6 months (approximately 180 days) prior to the Screening visit. 6. Subject who received any vaccine (live, inactivated, or bacterial) within 1 month (approximately 30 days) prior to the Screening visit. 7. Subject with hypersensitivity to the ingredients of AdimrSC-2f (including aluminum). 8. Subject with personal or family history of Guillain-Barré Syndrome. 9. Subject who has travelled abroad within 3 months (approximately 90 days) prior to the Screening visit. 10. Subject with influenza-like illness as defined by any of the following symptoms at Screening visit: fever (tympanic temperature ≥ 38℃), dry cough, headache, fatigue, respiratory sputum production (phlegm), dysgeusia, anosmia, shortness of breath, muscle and joint pain, or sore throat. 11. Female subject who is pregnant or lactating at screening or plans to be pregnant during the study period. 12. Subject who treated with an investigational drug or device or have participated in a clinical study within 3 months (approximately 90 days) prior to the Screening visit. 13. Subject with clinically significant abnormal ECG at the Screening visit or with history of clinically significant cardiovascular disease such as arrhythmia, coronary artery disease or heart failure, as judged by the investigator. 14. Subject with any confirmed or suspected abnormal immune function, immunosuppressive, or immunodeficiency or received any immunosuppressants or immunomodulators within 6 months (approximately 180 days) prior to the Screening visit. 15. Subject with history of wheezing, asthma, chronic obstructive pulmonary disease, or have used bronchodilator within 3 months (approximately 90 days) prior to the Screening visit. 16. Subject who had blood donation within 2 weeks prior to the Screening visit. 17. Subject who received any blood products, including immunoglobulin within 3 months (approximately 90 days) prior to the Screening visit. 18. Subject who is not suitable to participate in this study as judged by the investigator. 19. Subject with chronic illness.