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.

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.

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.

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.