Inclusion Criteria:  Adult men and women ≥18 year-old and ≤55-year-old. Signed informed consent. No respiratory disease within last 21 days prior to first dose administration. Body Mass Index from 18.0 to 29.0 kg/m2. Negative RT-PCR for SARS-Cov-2 infection. Negative test for anti-SARS-CoV-2 IgM and IgG antibodies. O2 saturation ≥92% by pulse oximetry. Normal CT scan of thorax. No symptoms from clinical history and normal physical exam at screening visit. Lab test values within normal ranges for all the following:  Urinalysis. Liver enzymes. Renal function tests. Cholesterol and Triglycerides. Fasting glucose. Hematology.  Negative test for HBsAg, anti-HCV and anti-HIV antibodies. Negative VDRL test. Normal electrocardiogram. Negative pregnancy test for women with childbearing potential. Agreement of all sexually- active volunteers to use highly effective contraceptives over the study period and up to 30 days after the last administration of the experimental vaccine. Commitment from all participants to keep social distancing, use of mask and frequent hand washing with soap or antibacterial gel during the study period.  Exclusion Criteria:  History of hypersensitivity or allergy to any ingredient of the vaccine. History of severe anaphylactic reaction. History of seizures. History of chronic diseases or cancer. Vaccination against SARS-CoV-2 with approved or experimental vaccines. Participation in any other study with an experimental intervention within the last 3 months. Administration of any other drug or herbal preparation within the last 30 days. Any vaccine administered within the last 30 days, including influenza vaccine. Fever at the time of entry. Blood transfusion or blood components transfusion within the last 4 months. Regular activity related to work, social interaction or entertainment that represents an exposure to SARS-Cov-2 higher than that of the general population, as per investigator judgement. Drug and alcohol abuse. Any medical or not medical condition that could interfere with patient safety, study compliance or data interpretation, as per investigator judgement.