Anti-COVID19 AKS-452 Fusion Protein Vaccine - ACT Study

Inclusion Criteria: SARS-CoV-2 serology by Akston (a quantitative anti-SARS-Cov-2 SP/RBD-specific IgG ELISA): * Undetectable or \< 5 μg/mL titer and no known prior SARS-Cov-2 infection * Body mass index (BMI) between 19.0 and 30.0 kg/m2, inclusive * General good health, without significant medical illness, as determined via physical exam findings, ECG or vital signs * Note: one retest of vital functions and ECG is allowed within the screening window \- No clinically significant laboratory abnormalities as determined by the investigator * Note: one retest of lab tests is allowed within the screening window * Informed Consent Form signed voluntarily before any study-related procedure is performed, indicating that the subject understands the purpose and procedures required for the study and is willing to participate in the study * Willing to adhere to the prohibitions and restrictions specified in this protocol * Non-smoker (including prior smokers having stopped smoking for more than 3 months at time of screening) or non-habitual smoker (habitual smokers are persons who smoke more than 4 cigarettes or other tobacco products on a weekly basis) and agree to not use tobacco products during confinement. * Negative alcohol breath test and urine drug screen at screening and upon check-in at the clinical site. * Negative hepatitis panel (including hepatitis B surface Ag and anti-hepatitis C virus Abs) and negative human immunodeficiency virus Ab and Ag screens at screening * Female subjects should fulfil one of the following criteria: * At least 1 year post-menopausal (amenorrhea \>12 months and/or follicle stimulating hormone \>30 mIU/mL) at screening; * Surgically sterile (bilateral oophorectomy, hysterectomy, or tubal ligation); * Will use adequate forms of contraceptives from screening to discharge. \- Female subjects of childbearing potential and male subjects who are sexually active with a female partner of childbearing potential must agree to the use of an effective method of birth control from screening to discharge * Note: medically acceptable methods of contraception that may be used by the subject and/or partner include combined oral contraceptive, contraceptive vaginal ring, contraceptive injection, intrauterine device, etonogestrel implant, double barrier, sterilization and vasectomy \- Female subject has a negative pregnancy test at screening and upon check-in at the clinical site. * Note: pregnancy testing will consist of a serum pregnancy test at screening and urine pregnancy tests at other (dosing) visits, in all women. Exclusion Criteria: A potential subject who meets any of the following criteria will be excluded from participation in this study: * Pregnant of breastfeeding females * Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, hematologic, rheumatologic, endocrine, autoimmune, or renal disease * Any laboratory test which is abnormal, and which is deemed by the Investigator(s) to be clinically significant * Behavioral or cognitive impairment or psychiatric disease that in the opinion of the investigator affects the ability of the subject to understand and cooperate with the study protocol * Current alcohol/illicit drug/nicotine abuse or addiction: history or evidence of current drug use or addiction (positive drug screen for amphetamines, barbiturates, benzodiazepines, cannabinoids, cocaine, or opiates) or excessive use of alcohol at screening and Day -2. * Presence of any febrile illness (T \> = 38.0°C or lab confirmed viral disease (PCR)) or symptoms suggestive of a viral respiratory infection within 1 weeks prior to vaccination * Use of corticosteroids (excluding topical preparations for cutaneous or nasal use) or use of immunosuppressive drugs within 30 days before inoculation * A history of anaphylaxis, history of allergic reaction to vaccine, known allergy to one of the components in AKS-452. Mild allergies without angio-oedema or treatment need can be included if deemed not to be of clinical significance (including but not limited to allergy to animals or mild seasonal hay fever) * A history of asthma within the past 10 years, or a current diagnosis of asthma or reactive airway disease associated with exercise * Receipt of a licensed vaccine within 4 weeks prior to viral inoculation * Received any experimental SARA-CoV-2 vaccine or drug * Receipt of blood or blood-derived products (including immunoglobulin) within 6 months prior to vaccination. * Receipt of another investigational agent within 30 days or 5 times the product half-life (whichever is longest) prior to vaccination * Shares household with /works with immunocompromised individual(s), adults with significant cardiopulmonary disease, persons with significant asthma, institutionalized elderly or elderly with functional disability * Deprived of freedom by an administrative or court order or in an emergency setting - Any condition that in the opinion of the principal investigator (PI) would jeopardize the safety or rights of a person participating in the trial or would render the person unable to comply with the protocol.