Phase I Study to Assess the Safety and Immunology of a COVID-19 Vaccine With GRAd-COV2 Vaccine

Inclusion Criteria: A subject must meet all of the following criteria to be eligible to participate in this study: 1. Provides written informed consent prior to initiation of any study procedures. 2. Be able to understand and agrees to comply with planned study procedures and be available for all study visits. 3. Agrees to the collection of venous blood per protocol. 4. Confirms to have not donated blood three months before the study 5. Agrees to refrain from blood during the study and until the three months after the end of the study. 6. Body Mass Index 18-29 kg/m2, inclusive, at screening. 7. Premenopausal women must agree to use one acceptable primary form of contraception. 8. Premenopausal women must have a negative urine pregnancy test the day of vaccination and are routinely using - and willing to use up to six months from vaccine administration - an effective method of birth control resulting in a low failure rate (i.e., hormonal contraception, condoms in combination with a spermicidal cream, male partner sterilization-vasectomy or total sexual abstinence). 9. Oral temperature ≤37.0 degrees Celsius the day of the administration of the vaccine 10. Pulse no greater than 100 beats per minute. 11. Systolic blood pressure (BP) is 85 to 139 mmHg, inclusive the day of vaccination. 12. Should not show laboratory values outside the normal range which may have clinical significance even in absence of specific signs or symptoms. Exclusion Criteria: A subject who meets any of the following criteria will be excluded from participation in this study: 1. Positive serology for anti-HIV-Ab 2. Positive HbBsAg 3. Positive anti-HCV-Ab 4. Positive for SARS-CoV-2 (either anti-S-Ab or anti-N-Ab) 5. Acute illness, as determined by the site PI or appropriate sub-investigator, the day of vaccination. 6. Breastfeeding women 7. Autoimmune and hyper-inflammatory condition 8. History of atopy (or any IgE associated condition) who had required treatment over the last 6 months; 9. History of hypersensitivity or severe allergic reaction (e.g., anaphylaxis, generalized urticaria, angioedema, other significant reaction) to any previous licensed or unlicensed vaccines; 10. Assumption of any immunomodulatory medication over the last 4 months (including, but not limited to, systemic corticosteroids, allergy injections, immunoglobulin, interferon, immunomodulators, cytotoxic drugs, or other similar or toxic drugs). The use of low dose topical, ophthalmic, inhaled, and intranasal steroid preparations will be permitted. 11. Presence of self-reported or medically documented significant medical condition 12. Presence of self-reported or medically documented significant psychiatric condition 13. Significant cardiovascular disease needing therapy or history of myocarditis or pericarditis or heart surgery. Patients in treatment with Sartans or ACE-Inhibitors and good response to therapy may be included. 14. Neurological or neurodevelopmental conditions (e.g., history of migraines in the past 5 years, epilepsy, stroke, seizures in the last 3 years, encephalopathy, focal neurologic deficits, Guillain-Barré syndrome, encephalomyelitis or transverse myelitis). 15. Ongoing malignancy or recent diagnosis of malignancy in the last five years excluding basal cell and squamous cell carcinoma of the skin, which are allowed. 16. Primary or secondary immunodeficiency of any cause. 17. Participated in another investigational study involving vaccination of biologic compounds in the last 12 months. 18. Currently enrolled in or plans to participate in another clinical trial with an investigational agent that will be received during the study-reporting period. 19. Administration of immunoglobulins and/or any blood or blood products within the 4 months before the first vaccine administration or at any time during the study. 20. Has any significant disorder of coagulation. 21. Has any chronic liver disease, including fatty liver. 22. Has a history of alcohol abuse or other recreational drug use within 6 months before the first vaccine administration. 23. Has any abnormality or permanent body art (e.g., tattoo) that would interfere with the ability to observe local reactions at the injection site (deltoid region). 24. Received or plans to receive additional vaccination within 4 weeks before or after each vaccination. 25. Has been reported as a case (confirmed or probable) of COVID-19 from the regional health system 26. Has any clinical conditions that, in the opinion of the site PI or appropriate sub-investigator, precludes study participation, this includes any acute, subacute, intermittent or chronic medical disease or condition that would place the subject at an unacceptable risk of injury, render the subject unable to meet the requirements of the protocol, or may interfere with the evaluation of responses or the subject's successful completion of this trial