Study of ZnAg Liquid Solution to Treat COVID-19 Symptomatic Participants

Inclusion Criteria: 1. Adults, aged 40 - 90 years (inclusive) 2. Acute onset (within 96 hours of the Baseline visit) of two or more COVID-19 symptoms self-rated as moderate-to-severe, including fever, myalgia, fatigue, chest tightness, chills, cough, diarrhea, gastrointestinal distress, headache, sore throat, congestion, or runny nose, ageusia, anosmia, nausea, tingling or numbness in the extremities, or shortness of breath. 3. Laboratory-confirmed SARS-CoV-2 infection as determined by positive PCR in a sample collected ≤ 96 hours prior to the Baseline visit. 4. PGI-Severity and CGI-Severity assessments of 'Mild', 'Moderate, or 'Severe' at the Screening visit (e.g., cannot be 'Normal'). 5. Participant (or legally authorized representatives) provides informed consent prior to the initiation of any study procedures. 6. Participant is willing and able to follow all study procedures and assessments according to the study protocol. 7. Participant is able to consume 60 ml of fluid orally twice daily. 8. Women of childbearing potential must agree to either abstinence or use at least one primary form of contraception, not including hormonal contraception from the time of screening through the end of study. Exclusion Criteria: 1. Unable or unwilling to take ZnAg liquid solution or matching placebo as directed. 2. Hospitalized prior to Baseline for COVID-19 management. 3. Need for hospitalization and/or ventilatory support at Baseline. 4. The emergence of any disease during study, other than COVID-19 that could better explain the participants' signs and symptoms. 5. Severe disease: respiratory distress, or requiring supplemental oxygen, or SpO2 ≤ 93% on room air, or tachypnea (respiratory rate ≥ 30 breaths/min) at Baseline. 6. History or presence of serious or acute heart disease such as uncontrolled cardiac dysrhythmia or arrhythmia, uncontrolled angina pectoris, cardiomyopathy, or uncontrolled congestive heart failure (NYHA class 3 or 4). 7. Legal incapacity or limited legal capacity. 8. Women of childbearing potential who do not agree to use either abstinence or at least one primary form of contraception, not including hormonal contraception from the time of screening through the end of the study. 9. Pregnant or breastfeeding. 10. Participation in another clinical study with an investigational product within the prior 12 months (per Resolution 251/1997).