Inclusion Criteria:

• Age ≥ 50 years old OR primary healthcare professional (defined as having a job that has had direct patient contact during the COVID-19 pandemic) and ≥ 18 years old.
• No symptoms of COVID-19 (a fever of 100.0 degrees F or greater, OR a new cough, OR new shortness of breath, OR new sore throat, OR new diarrhea, OR new fast breathing (respiratory distress), OR new chills, OR new muscle aches (myalgias), OR new loss of smell, OR new change or loss of taste sensation) in the past 7 days.
• Have a negative Elecsys Anti-SARS-CoV-2 immunoassay antibody test at screening .
• Have not had close contact with a person with a LABORATORY CONFIRMED case of COVID-19 (Close contact is defined by CDC as:  being within approximately 6 feet of a COVID-19 patient for a prolonged period of time (more than 5 minutes) or having direct contact with infectious secretions of a COVID-19 patient (e.g., being coughed on)) in the last 14 days.
• Mayo Clinic patient who has a patient online account set up or is willing to set up an online account.
• Must have a valid email address and internet service

Exclusion Criteria:

• History of positive or indeterminate COVID PCR test prior to screening or positive or indeterminate Elecsys Anti-SARS-CoV-2 immunoassay antibody test at screening.
• Active symptoms of COVID ((a fever of 100.0 degrees F or greater, OR a new cough, OR new shortness of breath, OR new sore throat, OR new diarrhea, OR new fast breathing (respiratory distress), OR new chills, OR new muscle aches (myalgias), OR new loss of smell, OR new change or loss of taste sensation)) in past 7 days.
• Known intolerance to Centrum multivitamins or Zinc supplement from prior exposure.
• Inability to complete follow-up questions or grant access to electronic health record for surveillance.
• Have had close contact with a person with a LABORATORY CONFIRMED case of COVID-19 in past 14 days.
• Current or former smoker less than 5 years ago.
• Pregnant or breastfeeding.
• Prisoner.
• Any subject with known immunosuppressed state, including:
  • A history of solid organ or bone marrow transplantation;
  • Subjects currently receiving chemotherapy;
  • Current rheumatologic or autoimmune illness requiring treatment with glucocorticoids, antimetabolite agents (methotrexate, azathioprine, mercaptopurine, fluorouracil, mycophenolate, leflunomide), IMIDs (lenalidomide, thalidomide, pomalidomide), calcineurin inhibitors (tacrolimus, cyclosporine), mTOR inhibitors (sirolimus, everolimus), or any monoclonal antibody drugs (including any drug given intravenously or subcutaneously) for the purpose of immunosuppression;
  • Subjects with HIV or primary immunodeficiency syndromes.