inclusion criteria: 1. male and female participants ≥18 years of age with 1 or more co-morbidities. 2. for the co-morbidities chronic kidney disease, chronic obstructive pulmonary disease (copd), chronic cardiovascular disease and diabetes mellitus, the first 25 participants per co-morbidity should include only mild to moderate cases. thereafter, more severe conditions may be recruited following internal safety review committee (isrc) and data safety monitoring board (dsmb) chair approval. 3. participant has no overt clinical signs or symptoms of covid-19. 4. participant has to sign the informed consent form (icf) before any trial procedures. 5. participants with a life expectancy of at least 1 year as per the investigator's assessment. 6. expected to be compliant with protocol procedures and available for clinical follow-up through the last planned visit. 7. physical examination without acute clinically significant findings according to the investigator's assessment. 8. female participants: at the time of enrollment, negative human chorionic gonadotropin (hcg) pregnancy test (serum) for women presumed to be of childbearing potential on the day of enrollment. on day 1 (pre vaccination): negative urine pregnancy test (hcg) (only required if serum pregnancy test was performed more than 3 days before). note: women that are postmenopausal (defined as amenorrhea for ≥ 12 consecutive months prior to screening without an alternative medical cause) or permanently sterilized will be considered as not having reproductive potential. 9. female participants of childbearing potential must use highly effective methods of birth control from 2 weeks before the first administration of the trial vaccine until 3 months following the last administration.

inclusion criteria: 1. male and female participants ≥18 years of age with 1 or more co-morbidities. 2. for the co-morbidities chronic kidney disease, chronic obstructive pulmonary disease (copd), chronic cardiovascular disease and diabetes mellitus, the first 25 participants per co-morbidity should include only mild to moderate cases. thereafter, more severe conditions may be recruited following internal safety review committee (isrc) and data safety monitoring board (dsmb) chair approval. 3. participant has no overt clinical signs or symptoms of covid-19. 4. participant has to sign the informed consent form (icf) before any trial procedures. 5. participants with a life expectancy of at least 1 year as per the investigator's assessment. 6. expected to be compliant with protocol procedures and available for clinical follow-up through the last planned visit. 7. physical examination without acute clinically significant findings according to the investigator's assessment. 8. female participants: at the time of enrollment, negative human chorionic gonadotropin (hcg) pregnancy test (serum) for women presumed to be of childbearing potential on the day of enrollment. on day 1 (pre vaccination): negative urine pregnancy test (hcg) (only required if serum pregnancy test was performed more than 3 days before). note: women that are postmenopausal (defined as amenorrhea for ≥ 12 consecutive months prior to screening without an alternative medical cause) or permanently sterilized will be considered as not having reproductive potential. 9. female participants of childbearing potential must use highly effective methods of birth control from 2 weeks before the first administration of the trial vaccine until 3 months following the last administration.

inclusion criteria: male and female participants ≥18 years of age with 1 or more co-morbidities. for the co-morbidities chronic kidney disease, chronic obstructive pulmonary disease (copd), chronic cardiovascular disease and diabetes mellitus, the first 25 participants per co-morbidity should include only mild to moderate cases. thereafter, more severe conditions may be recruited following internal safety review committee (isrc) and data safety monitoring board (dsmb) chair approval. participant has no overt clinical signs or symptoms of covid-19. participant has to sign the informed consent form (icf) before any trial procedures. participants with a life expectancy of at least 1 year as per the investigator's assessment. expected to be compliant with protocol procedures and available for clinical follow-up through the last planned visit. physical examination without acute clinically significant findings according to the investigator's assessment. female participants: at the time of enrollment, negative human chorionic gonadotropin (hcg) pregnancy test (serum) for women presumed to be of childbearing potential on the day of enrollment. on day 1 (pre vaccination): negative urine pregnancy test (hcg) (only required if serum pregnancy test was performed more than 3 days before). note: women that are postmenopausal (defined as amenorrhea for ≥ 12 consecutive months prior to screening without an alternative medical cause) or permanently sterilized will be considered as not having reproductive potential. female participants of childbearing potential must use highly effective methods of birth control from 2 weeks before the first administration of the trial vaccine until 3 months following the last administration .

inclusion criteria: male and female participants ≥18 years of age with 1 or more co-morbidities. for the co-morbidities chronic kidney disease, chronic obstructive pulmonary disease (copd), chronic cardiovascular disease and diabetes mellitus, the first 25 participants per co-morbidity should include only mild to moderate cases. thereafter, more severe conditions may be recruited following internal safety review committee (isrc) and data safety monitoring board (dsmb) chair approval. participant has no overt clinical signs or symptoms of covid-19. participant has to sign the informed consent form (icf) before any trial procedures. participants with a life expectancy of at least 1 year as per the investigator's assessment. expected to be compliant with protocol procedures and available for clinical follow-up through the last planned visit. physical examination without acute clinically significant findings according to the investigator's assessment. female participants: at the time of enrollment, negative human chorionic gonadotropin (hcg) pregnancy test (serum) for women presumed to be of childbearing potential on the day of enrollment. on day 1 (pre vaccination): negative urine pregnancy test (hcg) (only required if serum pregnancy test was performed more than 3 days before). note: women that are postmenopausal (defined as amenorrhea for ≥ 12 consecutive months prior to screening without an alternative medical cause) or permanently sterilized will be considered as not having reproductive potential. female participants of childbearing potential must use highly effective methods of birth control from 2 weeks before the first administration of the trial vaccine until 3 months following the last administration .

inclusion criteria: 1. male and female participants ≥18 years of age with 1 or more co-morbidities. 2. for the co-morbidities chronic kidney disease, chronic obstructive pulmonary disease (copd), chronic cardiovascular disease and diabetes mellitus, the first 25 participants per co-morbidity should include only mild to moderate cases. thereafter, more severe conditions may be recruited following internal safety review committee (isrc) and data safety monitoring board (dsmb) chair approval. 3. participant has no overt clinical signs or symptoms of covid-19. 4. participant has to sign the informed consent form (icf) before any trial procedures. 5. participants with a life expectancy of at least 1 year as per the investigator's assessment. 6. expected to be compliant with protocol procedures and available for clinical follow-up through the last planned visit. 7. physical examination without acute clinically significant findings according to the investigator's assessment. 8. female participants: at the time of enrollment, negative human chorionic gonadotropin (hcg) pregnancy test (serum) for women presumed to be of childbearing potential on the day of enrollment. on day 1 (pre vaccination): negative urine pregnancy test (hcg) (only required if serum pregnancy test was performed more than 3 days before). note: women that are postmenopausal (defined as amenorrhea for ≥ 12 consecutive months prior to screening without an alternative medical cause) or permanently sterilized will be considered as not having reproductive potential. 9. female participants of childbearing potential must use highly effective methods of birth control from 2 weeks before the first administration of the trial vaccine until 3 months following the last administration .

inclusion criteria: 1. male and female participants ≥18 years of age with 1 or more co-morbidities. 2. for the co-morbidities chronic kidney disease, chronic obstructive pulmonary disease (copd), chronic cardiovascular disease and diabetes mellitus, the first 25 participants per co-morbidity should include only mild to moderate cases. thereafter, more severe conditions may be recruited following internal safety review committee (isrc) and data safety monitoring board (dsmb) chair approval. 3. participant has no overt clinical signs or symptoms of covid-19. 4. participant has to sign the informed consent form (icf) before any trial procedures. 5. participants with a life expectancy of at least 1 year as per the investigator's assessment. 6. expected to be compliant with protocol procedures and available for clinical follow-up through the last planned visit. 7. physical examination without acute clinically significant findings according to the investigator's assessment. 8. female participants: at the time of enrollment, negative human chorionic gonadotropin (hcg) pregnancy test (serum) for women presumed to be of childbearing potential on the day of enrollment. on day 1 (pre vaccination): negative urine pregnancy test (hcg) (only required if serum pregnancy test was performed more than 3 days before). note: women that are postmenopausal (defined as amenorrhea for ≥ 12 consecutive months prior to screening without an alternative medical cause) or permanently sterilized will be considered as not having reproductive potential. 9. female participants of childbearing potential must use highly effective methods of birth control from 2 weeks before the first administration of the trial vaccine until 3 months following the last administration .