a participant will be excluded if one or more of the following conditions apply: 1. known sars-cov-2 infection or positive test result within 6 months prior to day 1 2. ongoing prophylactic covid-19 treatment, or monoclonal antibody infusion within 6 months prior to day 1 3. any covid-19 vaccination within 6 months prior to day 1 4. exhibits symptoms consistent with covid-19 as assessed by study clinician such as: fever, dry cough, fatigue, nasal obstruction, runny nose, sore throat, myalgia, diarrhea, shortness of breath or dyspnea within 14 days prior to in day 1 5. known close contact (as defined by cdc, 2021a) with someone who has covid-19 within 14 days prior to day 1 6. history or presence of self-reported or medically documented significant medical or psychiatric condition(s) as assessed by study clinician, including: 1. at high risk of severe covid-19 disease, such as significant history of copd or chronic lung disease, chronic kidney disease, serious heart conditions (such as heart failure, coronary artery disease or cardiomyopathies), sickle cell disease, diabetes 2. clinically significant central nervous system disease such as epilepsy, encephalopathy, or a history of severe mental illness 3. severe liver and/or kidney diseases, uncontrolled hypertension, or ongoing or highly likely to recur malignancies 4. ongoing or recent clinically significant history of alcohol or drug abuse 7. active participation in an interventional clinical study with an investigational drug/biologic/device agent receipt of any specimen collection within 30 days prior to day 1 8. evidence of infection with hepatitis b virus or hepatitis c virus 9. positive test result for human immunodeficiency virus (hiv) with the exception that 30% of participants may be hiv-infected, if stable on antiretrovirals with stable cd4 \>350 cells/mm3 and virally suppressed 10. history of myocarditis or pericarditis 11. diagnosed with congenital or acquired immune deficiency, ongoing lymphoma, leukemia, or other clinically significant immune compromising or autoimmune conditions. 12. history of known coagulation dysfunction (e.g., coagulation factor deficiency, known thrombocytopenia, platelet dysfunction, coagulation disease, etc.) 13. receipt of any live attenuated vaccine within 30 days, or with any other (non-live) vaccine within 14 days prior to day 1 14. received more than 10 days of any systemic immunosuppressants or cytotoxic medications within 30 days prior to day 1, any within 14 days prior to day 1 or is anticipating the need for immunosuppressants at any time during participation in the study. 15. received any blood products within 3 months prior to day 1 16. donated \> 450 ml of whole blood within 30 days prior to day 1 17. history of unexplained or recurrent anaphylaxis or angioedema, or a history of severe allergic reaction (e.g., anaphylaxis) after a previous dose of any vaccine, or to any component of vxco-100. 18. for persons of childbearing potential: breastfeeding or planning to become pregnant during trial duration. 19. any condition that, in the opinion of the investigator, would (a) pose a health risk to the participant if enrolled or (b) could interfere with evaluation of the study vaccine or interpretation of study results.

a participant will be excluded if one or more of the following conditions apply: 1. known sars-cov-2 infection or positive test result within 6 months prior to day 1 2. ongoing prophylactic covid-19 treatment, or monoclonal antibody infusion within 6 months prior to day 1 3. any covid-19 vaccination within 6 months prior to day 1 4. exhibits symptoms consistent with covid-19 as assessed by study clinician such as: fever, dry cough, fatigue, nasal obstruction, runny nose, sore throat, myalgia, diarrhea, shortness of breath or dyspnea within 14 days prior to in day 1 5. known close contact (as defined by cdc, 2021a) with someone who has covid-19 within 14 days prior to day 1 6. history or presence of self-reported or medically documented significant medical or psychiatric condition(s) as assessed by study clinician, including: 1. at high risk of severe covid-19 disease, such as significant history of copd or chronic lung disease, chronic kidney disease, serious heart conditions (such as heart failure, coronary artery disease or cardiomyopathies), sickle cell disease, diabetes 2. clinically significant central nervous system disease such as epilepsy, encephalopathy, or a history of severe mental illness 3. severe liver and/or kidney diseases, uncontrolled hypertension, or ongoing or highly likely to recur malignancies 4. ongoing or recent clinically significant history of alcohol or drug abuse 7. active participation in an interventional clinical study with an investigational drug/biologic/device agent receipt of any specimen collection within 30 days prior to day 1 8. evidence of infection with hepatitis b virus or hepatitis c virus 9. positive test result for human immunodeficiency virus (hiv) with the exception that 30% of participants may be hiv-infected, if stable on antiretrovirals with stable cd4 \>350 cells/mm3 and virally suppressed 10. history of myocarditis or pericarditis 11. diagnosed with congenital or acquired immune deficiency, ongoing lymphoma, leukemia, or other clinically significant immune compromising or autoimmune conditions. 12. history of known coagulation dysfunction (e.g., coagulation factor deficiency, known thrombocytopenia, platelet dysfunction, coagulation disease, etc.) 13. receipt of any live attenuated vaccine within 30 days, or with any other (non-live) vaccine within 14 days prior to day 1 14. received more than 10 days of any systemic immunosuppressants or cytotoxic medications within 30 days prior to day 1, any within 14 days prior to day 1 or is anticipating the need for immunosuppressants at any time during participation in the study. 15. received any blood products within 3 months prior to day 1 16. donated \> 450 ml of whole blood within 30 days prior to day 1 17. history of unexplained or recurrent anaphylaxis or angioedema, or a history of severe allergic reaction (e.g., anaphylaxis) after a previous dose of any vaccine, or to any component of vxco-100. 18. for persons of childbearing potential: breastfeeding or planning to become pregnant during trial duration. 19. any condition that, in the opinion of the investigator, would (a) pose a health risk to the participant if enrolled or (b) could interfere with evaluation of the study vaccine or interpretation of study results.

a participant will be excluded if one or more of the following conditions apply: known sars-cov-2 infection or positive test result within 6 months prior to day 1 ongoing prophylactic covid-19 treatment, or monoclonal antibody infusion within 6 months prior to day 1 any covid-19 vaccination within 6 months prior to day 1 exhibits symptoms consistent with covid-19 as assessed by study clinician such as: fever, dry cough, fatigue, nasal obstruction, runny nose, sore throat, myalgia, diarrhea, shortness of breath or dyspnea within 14 days prior to in day 1 known close contact (as defined by cdc, 2021a) with someone who has covid-19 within 14 days prior to day 1 history or presence of self-reported or medically documented significant medical or psychiatric condition(s) as assessed by study clinician, including: at high risk of severe covid-19 disease, such as significant history of copd or chronic lung disease, chronic kidney disease, serious heart conditions (such as heart failure, coronary artery disease or cardiomyopathies), sickle cell disease, diabetes clinically significant central nervous system disease such as epilepsy, encephalopathy, or a history of severe mental illness severe liver and/or kidney diseases, uncontrolled hypertension, or ongoing or highly likely to recur malignancies ongoing or recent clinically significant history of alcohol or drug abuse active participation in an interventional clinical study with an investigational drug/biologic/device agent receipt of any specimen collection within 30 days prior to day 1 evidence of infection with hepatitis b virus or hepatitis c virus positive test result for human immunodeficiency virus (hiv) with the exception that 30% of participants may be hiv-infected, if stable on antiretrovirals with stable cd4 >350 cells/mm3 and virally suppressed history of myocarditis or pericarditis diagnosed with congenital or acquired immune deficiency, ongoing lymphoma, leukemia, or other clinically significant immune compromising or autoimmune conditions. history of known coagulation dysfunction (e.g., coagulation factor deficiency, known thrombocytopenia, platelet dysfunction, coagulation disease, etc.) receipt of any live attenuated vaccine within 30 days, or with any other (non-live) vaccine within 14 days prior to day 1 received more than 10 days of any systemic immunosuppressants or cytotoxic medications within 30 days prior to day 1, any within 14 days prior to day 1 or is anticipating the need for immunosuppressants at any time during participation in the study. received any blood products within 3 months prior to day 1 donated > 450 ml of whole blood within 30 days prior to day 1 history of unexplained or recurrent anaphylaxis or angioedema, or a history of severe allergic reaction (e.g., anaphylaxis) after a previous dose of any vaccine, or to any component of vxco-100. for persons of childbearing potential: breastfeeding or planning to become pregnant during trial duration. any condition that, in the opinion of the investigator, would (a) pose a health risk to the participant if enrolled or (b) could interfere with evaluation of the study vaccine or interpretation of study results.

a participant will be excluded if one or more of the following conditions apply: known sars-cov-2 infection or positive test result within 6 months prior to day 1 ongoing prophylactic covid-19 treatment, or monoclonal antibody infusion within 6 months prior to day 1 any covid-19 vaccination within 6 months prior to day 1 exhibits symptoms consistent with covid-19 as assessed by study clinician such as: fever, dry cough, fatigue, nasal obstruction, runny nose, sore throat, myalgia, diarrhea, shortness of breath or dyspnea within 14 days prior to in day 1 known close contact (as defined by cdc, 2021a) with someone who has covid-19 within 14 days prior to day 1 history or presence of self-reported or medically documented significant medical or psychiatric condition(s) as assessed by study clinician, including: at high risk of severe covid-19 disease, such as significant history of copd or chronic lung disease, chronic kidney disease, serious heart conditions (such as heart failure, coronary artery disease or cardiomyopathies), sickle cell disease, diabetes clinically significant central nervous system disease such as epilepsy, encephalopathy, or a history of severe mental illness severe liver and/or kidney diseases, uncontrolled hypertension, or ongoing or highly likely to recur malignancies ongoing or recent clinically significant history of alcohol or drug abuse active participation in an interventional clinical study with an investigational drug/biologic/device agent receipt of any specimen collection within 30 days prior to day 1 evidence of infection with hepatitis b virus or hepatitis c virus positive test result for human immunodeficiency virus (hiv) with the exception that 30% of participants may be hiv-infected, if stable on antiretrovirals with stable cd4 >350 cells/mm3 and virally suppressed history of myocarditis or pericarditis diagnosed with congenital or acquired immune deficiency, ongoing lymphoma, leukemia, or other clinically significant immune compromising or autoimmune conditions. history of known coagulation dysfunction (e.g., coagulation factor deficiency, known thrombocytopenia, platelet dysfunction, coagulation disease, etc.) receipt of any live attenuated vaccine within 30 days, or with any other (non-live) vaccine within 14 days prior to day 1 received more than 10 days of any systemic immunosuppressants or cytotoxic medications within 30 days prior to day 1, any within 14 days prior to day 1 or is anticipating the need for immunosuppressants at any time during participation in the study. received any blood products within 3 months prior to day 1 donated > 450 ml of whole blood within 30 days prior to day 1 history of unexplained or recurrent anaphylaxis or angioedema, or a history of severe allergic reaction (e.g., anaphylaxis) after a previous dose of any vaccine, or to any component of vxco-100. for persons of childbearing potential: breastfeeding or planning to become pregnant during trial duration. any condition that, in the opinion of the investigator, would (a) pose a health risk to the participant if enrolled or (b) could interfere with evaluation of the study vaccine or interpretation of study results.

a participant will be excluded if one or more of the following conditions apply: known sars-cov-2 infection or positive test result within 6 months prior to day 1 ongoing prophylactic covid-19 treatment, or monoclonal antibody infusion within 6 months prior to day 1 any covid-19 vaccination within 6 months prior to day 1 exhibits symptoms consistent with covid-19 as assessed by study clinician such as: fever, dry cough, fatigue, nasal obstruction, runny nose, sore throat, myalgia, diarrhea, shortness of breath or dyspnea within 14 days prior to in day 1 known close contact (as defined by cdc, 2021a) with someone who has covid-19 within 14 days prior to day 1 history or presence of self-reported or medically documented significant medical or psychiatric condition(s) as assessed by study clinician, including: at high risk of severe covid-19 disease, such as significant history of copd or chronic lung disease, chronic kidney disease, serious heart conditions (such as heart failure, coronary artery disease or cardiomyopathies), sickle cell disease, diabetes clinically significant central nervous system disease such as epilepsy, encephalopathy, or a history of severe mental illness severe liver and/or kidney diseases, uncontrolled hypertension, or ongoing or highly likely to recur malignancies ongoing or recent clinically significant history of alcohol or drug abuse current participation in an interventional clinical study with an investigational drug/biologic/device agent or receipt of any investigational agent within 30 days prior to day 1 evidence of infection with hepatitis b virus or hepatitis c virus positive test result for human immunodeficiency virus (hiv) with the exception that 30% of participants may be hiv-infected, if stable on antiretrovirals with stable cd4 >350 cells/mm3 and virally suppressed history of myocarditis or pericarditis diagnosed with congenital or acquired immune deficiency, ongoing lymphoma, leukemia, or other clinically significant immune compromising or autoimmune conditions. history of known coagulation dysfunction (e.g., coagulation factor deficiency, known thrombocytopenia, platelet dysfunction, coagulation disease, etc.) receipt of any live attenuated vaccine within 30 days, or with any other (non-live) vaccine within 14 days prior to day 1 received more than 10 days of any systemic immunosuppressants or cytotoxic medications within 30 days prior to day 1, any within 14 days prior to day 1 or is anticipating the need for immunosuppressants at any time during participation in the study. received any blood products within 3 months prior to day 1 donated > 450 ml of whole blood within 30 days prior to day 1 history of unexplained or recurrent anaphylaxis or angioedema, or a history of severe allergic reaction (e.g., anaphylaxis) after a previous dose of any vaccine, or to any component of vxco-100. for persons of childbearing potential: breastfeeding or planning to become pregnant during trial duration. any condition that, in the opinion of the investigator, would (a) pose a health risk to the participant if enrolled or (b) could interfere with evaluation of the study vaccine or interpretation of study results.

a participant will be excluded if one or more of the following conditions apply: known sars-cov-2 infection or positive test result within 6 months prior to day 1 ongoing prophylactic covid-19 treatment, or monoclonal antibody infusion within 6 months prior to day 1 any covid-19 vaccination within 6 months prior to day 1 exhibits symptoms consistent with covid-19 as assessed by study clinician such as: fever, dry cough, fatigue, nasal obstruction, runny nose, sore throat, myalgia, diarrhea, shortness of breath or dyspnea within 14 days prior to in day 1 known close contact (as defined by cdc, 2021a) with someone who has covid-19 within 14 days prior to day 1 history or presence of self-reported or medically documented significant medical or psychiatric condition(s) as assessed by study clinician, including: at high risk of severe covid-19 disease, such as significant history of copd or chronic lung disease, chronic kidney disease, serious heart conditions (such as heart failure, coronary artery disease or cardiomyopathies), sickle cell disease, diabetes clinically significant central nervous system disease such as epilepsy, encephalopathy, or a history of severe mental illness severe liver and/or kidney diseases, uncontrolled hypertension, or ongoing or highly likely to recur malignancies ongoing or recent clinically significant history of alcohol or drug abuse current participation in an interventional clinical study with an investigational drug/biologic/device agent or receipt of any investigational agent within 30 days prior to day 1 evidence of infection with hepatitis b virus or hepatitis c virus positive test result for human immunodeficiency virus (hiv) with the exception that 30% of participants may be hiv-infected, if stable on antiretrovirals with stable cd4 >350 cells/mm3 and virally suppressed history of myocarditis or pericarditis diagnosed with congenital or acquired immune deficiency, ongoing lymphoma, leukemia, or other clinically significant immune compromising or autoimmune conditions. history of known coagulation dysfunction (e.g., coagulation factor deficiency, known thrombocytopenia, platelet dysfunction, coagulation disease, etc.) receipt of any live attenuated vaccine within 30 days, or with any other (non-live) vaccine within 14 days prior to day 1 received more than 10 days of any systemic immunosuppressants or cytotoxic medications within 30 days prior to day 1, any within 14 days prior to day 1 or is anticipating the need for immunosuppressants at any time during participation in the study. received any blood products within 3 months prior to day 1 donated > 450 ml of whole blood within 30 days prior to day 1 history of unexplained or recurrent anaphylaxis or angioedema, or a history of severe allergic reaction (e.g., anaphylaxis) after a previous dose of any vaccine, or to any component of vxco-100. for persons of childbearing potential: breastfeeding or planning to become pregnant during trial duration. any condition that, in the opinion of the investigator, would (a) pose a health risk to the participant if enrolled or (b) could interfere with evaluation of the study vaccine or interpretation of study results.