Inclusion criteria:  Age 18 to 65 years of age Able to provide informed consent Able and willing to comply with study procedures For women of childbearing potential, able and willing to use an approved form of pregnancy prevention during the study Negative test result for the presence of SARS-CoV-2 IgM and IgG antibodies, which indicate recent or prior infection  Exclusion criteria:  Persons involved in the care of patients with COVID-19 and health care workers considered, in the opinion of the investigator, to be at increased risk of infection from SARS-CoV-2 Persons with symptoms in the past 2 weeks consistent with possible acute SARS-CoV-2 infection to include fever, loss of smell or taste Persons diagnosis of type 2 diabetes mellitus Persons with a diagnosis of chronic kidney disease Persons with a diagnosis of chronic obstructive pulmonary disease (COPD) Persons with a diagnosis of heart conditions to include heart failure, coronary artery disease, prior heart attack, cardiomyopathy Obesity (BMI of 30 kg/m2 or greater) Sickle cell disease Current or former smoker Current or planned pregnancy during the study Currently breastfeeding Current or past participation in a coronavirus (MERS-CoV, SARS-CoV-2) vaccine study, or receipt of a SARS-CoV-2 vaccine that has been approved by the FDA, including vaccines that have received Emergency Use Authorization (EUA) Administration of an investigational agent within 90 days of the 1st dose Administration of a vaccine within 2 weeks prior to the 1st dose Administration of immune globulin within 6 months of enrollment Administration of an anti-TNFα inhibitor such as infliximab, adalimumab, etanercept, or anti-CD20 monoclonal antibody rituximab within 6 months from enrollment Current daily treatment of systemic corticosteroids of 20 mg of prednisone or greater; or the equivalent dose of other systemic corticosteroids Treatment within the four weeks prior to enrollment with any drug intended for the prophylaxis or treatment of COVID-19 Any prior treatment with an anti-SARS-CoV-2 monoclonal antibody or immune serum Prior treatment with an anti-IL-6 inhibitor, anti-IL-1 inhibitor, anti-TNF monoclonal antibody, or anti-JAK inhibitor (see Appendix B exclusionary period for specific drugs) History of malignancy History of transplantation (any organ or bone marrow) Current or planned chemotherapy treatment for hematologic or solid tumor during study period History of other congenital or acquired immunodeficiency, excluding those with HIV infection who are taking highly active antiretroviral therapy and who have documentation of undetectable serum viral load History of PCR-confirmed infection with SARS-CoV-2 Not willing to allow storage and future use of samples for SARS-CoV-2 related research and who have a CD4 count > 200 cells/µL on two measures at least 3 months apart Prisoner or subjects who are compulsorily detained for treatment of a psychiatric illness  Any illness or condition that, in the opinion of the investigator, may affect the safety of the subject or the evaluation of a study endpoint  Exclusion criteria (ID + IN only):  History of chronic rhinosinusitis History of nasal septal defect or deviated nasal septum History of cleft palate History of nasal polyps History of other disorders that, in the opinion of the investigator, may adversely affect administration of intranasal vaccine