Inclusion Criteria:  Understands and agrees to comply with research procedures and provides written informed consent Physical and mental health meet criteria to participate, which includes factors associated with increased risk of exposure to SARS-CoV-2, such as age > 65, mild to moderate obesity (BMI 30-40), hypertension controlled with medication, drug controlled hyperlipidemia, diabetes controlled with medication, mild chronic lung disease Vein access permits for blood collection For people with reproductive ability, adequate contraception and negative pregnancy test for women  Exclusion Criteria:  Have active symptoms of COVID-19 infection Diagnosed with COVID-19 with a positive PCR test in the past 3 months Positive SARS-CoV-2 rapid antibody IgG test Positive pregnancy test Known to have immunodeficiency disease Are taking immunosuppresive drugs and/or corticosteroids in the long term Have a condition requiring oxygen supplementation Previously diagnosed with invasive cancer and receiving anti-cancer therapy in addition to hormonal therapy for breast or prostate cancer History of thromboembolism or genetic predisposition to thromboembolism, or being on anti-thromboembolic therapy other than low-dose aspirin Physical or mental disability that prevents you from carrying out normal daily activities In the Investigator's judgement, have illnesses or medical conditions that could preclude participation Excessive obesity: BMI > 40 Uncontrolled hypertension: systolic > 180, diastolic > 100 Not willing to sign written consent