1. patient is either asymptomatic or with baseline severity of moderate, sever, or critical covid-19. 2. pregnant or lactating women. 3. patients with shortness of breath at rest. 4. findings on physical examination or available imaging studies suggesting rapid disease progression of covid-19. 5. signs or symptoms indicative of pneumonia or any other lower respiratory tract disorders, or clinically significant findings in available lung imaging studies suggestive of such disorders. 6. need for immediate hospitalization, oxygen supplementation or mechanical ventilation. 7. obstructive airway diseases, including chronic obstructive pulmonary disease (copd) and asthma, or other respiratory disease that could exacerbate independent of covid-19. 8. use of remdesivir, chloroquine, hydroxychloroquine, convalescent plasma, other monoclonal antibody therapies, include regen-cov (casirivimab and imdevimab), bamlanivimab (plus etesevimab), dexamethasone, ivermectin, baricitinib, and other janus kinase inhibitors, bruton's tyrosine kinase inhibitors, tocilizumab (and other interleukin-6 inhibitors) and any other therapy with eua or approval and other investigational agents for covid-19. 9. patients who are participating in other clinical trials. 10. history of conditions associated with immunocompromise, or treatments known to affect the immune system, including but not limited to oral or intravenous corticosteroids, alkylating drugs, antimetabolites, cytotoxic drugs, other chemotherapy, radiation, immune-modulating biologics, within 30 days of screening. 11. barium enemas within the last 30 days. 12. taking otc or prescribed medicine which has compound as active ingredient. 13. any unstable or uncontrolled medical illnesses such as neurological disorders, cardiovascular disorders, diabetes, hepatic or renal disorders that per the investigator would intervene with the study conduct or study results interpretation. 14. any other medical, psychiatric, or social condition or occupational or other responsibility that in the judgment of the investigator would interfere with or serve as a contraindication to protocol adherence, assessment of safety, or a patient's ability to give informed consent or respond to the study procedures or questions during the personal visits or the video calls. 15. high-risk individuals are those who meet at least one of the following criteria: 1. aged ≥ 65 years 2. body mass index (bmi) \> 30 3. pregnancy 4. chronic kidney disease 5. diabetes 6. immunosuppressive disease or immunosuppressive treatment 7. cardiovascular disease (including congenital heart disease) or hypertension 8. chronic lung diseases (for example, chronic obstructive pulmonary disease, asthma \[moderate-to-severe\], interstitial lung disease, cystic fibrosis and pulmonary hypertension) 9. sickle cell disease 10. neurodevelopmental disorders (for example, cerebral palsy) or other conditions that confer medical complexity (for example, genetic or metabolic syndromes and severe congenital anomalies) 11. having a medical-related technological dependence (for example, tracheostomy, gastrostomy, or positive pressure ventilation \[not related to covid-19\] 12. exclusion is not limited to the medical conditions or factors listed above. the investigators have to consider the benefit-risk for an individual patient to determine other medical conditions or factors (for example, overweight, race or ethnicity) may also place individual patients at high risk for progression to severe covid-19 and be excluded.

1. patient is either asymptomatic or with baseline severity of moderate, sever, or critical covid-19. 2. pregnant or lactating women. 3. patients with shortness of breath at rest. 4. findings on physical examination or available imaging studies suggesting rapid disease progression of covid-19. 5. signs or symptoms indicative of pneumonia or any other lower respiratory tract disorders, or clinically significant findings in available lung imaging studies suggestive of such disorders. 6. need for immediate hospitalization, oxygen supplementation or mechanical ventilation. 7. obstructive airway diseases, including chronic obstructive pulmonary disease (copd) and asthma, or other respiratory disease that could exacerbate independent of covid-19. 8. use of remdesivir, chloroquine, hydroxychloroquine, convalescent plasma, other monoclonal antibody therapies, include regen-cov (casirivimab and imdevimab), bamlanivimab (plus etesevimab), dexamethasone, ivermectin, baricitinib, and other janus kinase inhibitors, bruton's tyrosine kinase inhibitors, tocilizumab (and other interleukin-6 inhibitors) and any other therapy with eua or approval and other investigational agents for covid-19. 9. patients who are participating in other clinical trials. 10. history of conditions associated with immunocompromise, or treatments known to affect the immune system, including but not limited to oral or intravenous corticosteroids, alkylating drugs, antimetabolites, cytotoxic drugs, other chemotherapy, radiation, immune-modulating biologics, within 30 days of screening. 11. barium enemas within the last 30 days. 12. taking otc or prescribed medicine which has compound as active ingredient. 13. any unstable or uncontrolled medical illnesses such as neurological disorders, cardiovascular disorders, diabetes, hepatic or renal disorders that per the investigator would intervene with the study conduct or study results interpretation. 14. any other medical, psychiatric, or social condition or occupational or other responsibility that in the judgment of the investigator would interfere with or serve as a contraindication to protocol adherence, assessment of safety, or a patient's ability to give informed consent or respond to the study procedures or questions during the personal visits or the video calls. 15. high-risk individuals are those who meet at least one of the following criteria: 1. aged ≥ 65 years 2. body mass index (bmi) \> 30 3. pregnancy 4. chronic kidney disease 5. diabetes 6. immunosuppressive disease or immunosuppressive treatment 7. cardiovascular disease (including congenital heart disease) or hypertension 8. chronic lung diseases (for example, chronic obstructive pulmonary disease, asthma \[moderate-to-severe\], interstitial lung disease, cystic fibrosis and pulmonary hypertension) 9. sickle cell disease 10. neurodevelopmental disorders (for example, cerebral palsy) or other conditions that confer medical complexity (for example, genetic or metabolic syndromes and severe congenital anomalies) 11. having a medical-related technological dependence (for example, tracheostomy, gastrostomy, or positive pressure ventilation \[not related to covid-19\] 12. exclusion is not limited to the medical conditions or factors listed above. the investigators have to consider the benefit-risk for an individual patient to determine other medical conditions or factors (for example, overweight, race or ethnicity) may also place individual patients at high risk for progression to severe covid-19 and be excluded.

patient is either asymptomatic or with baseline severity of moderate, sever, or critical covid-19. pregnant or lactating women. patients with shortness of breath at rest. findings on physical examination or available imaging studies suggesting rapid disease progression of covid-19. signs or symptoms indicative of pneumonia or any other lower respiratory tract disorders, or clinically significant findings in available lung imaging studies suggestive of such disorders. need for immediate hospitalization, oxygen supplementation or mechanical ventilation. obstructive airway diseases, including chronic obstructive pulmonary disease (copd) and asthma, or other respiratory disease that could exacerbate independent of covid-19. use of remdesivir, chloroquine, hydroxychloroquine, convalescent plasma, other monoclonal antibody therapies, include regen-cov (casirivimab and imdevimab), bamlanivimab (plus etesevimab), dexamethasone, ivermectin, baricitinib, and other janus kinase inhibitors, bruton's tyrosine kinase inhibitors, tocilizumab (and other interleukin-6 inhibitors) and any other therapy with eua or approval and other investigational agents for covid-19. patients who are participating in other clinical trials. history of conditions associated with immunocompromise, or treatments known to affect the immune system, including but not limited to oral or intravenous corticosteroids, alkylating drugs, antimetabolites, cytotoxic drugs, other chemotherapy, radiation, immune-modulating biologics, within 30 days of screening. barium enemas within the last 30 days. taking otc or prescribed medicine which has compound as active ingredient. any unstable or uncontrolled medical illnesses such as neurological disorders, cardiovascular disorders, diabetes, hepatic or renal disorders that per the investigator would intervene with the study conduct or study results interpretation. any other medical, psychiatric, or social condition or occupational or other responsibility that in the judgment of the investigator would interfere with or serve as a contraindication to protocol adherence, assessment of safety, or a patient's ability to give informed consent or respond to the study procedures or questions during the personal visits or the video calls. high-risk individuals are those who meet at least one of the following criteria: aged ≥ 65 years body mass index (bmi) > 30 pregnancy chronic kidney disease diabetes immunosuppressive disease or immunosuppressive treatment cardiovascular disease (including congenital heart disease) or hypertension chronic lung diseases (for example, chronic obstructive pulmonary disease, asthma [moderate-to-severe], interstitial lung disease, cystic fibrosis and pulmonary hypertension) sickle cell disease neurodevelopmental disorders (for example, cerebral palsy) or other conditions that confer medical complexity (for example, genetic or metabolic syndromes and severe congenital anomalies) having a medical-related technological dependence (for example, tracheostomy, gastrostomy, or positive pressure ventilation [not related to covid-19] exclusion is not limited to the medical conditions or factors listed above. the investigators have to consider the benefit-risk for an individual patient to determine other medical conditions or factors (for example, overweight, race or ethnicity) may also place individual patients at high risk for progression to severe covid-19 and be excluded.

patient is either asymptomatic or with baseline severity of moderate, sever, or critical covid-19. pregnant or lactating women. patients with shortness of breath at rest. findings on physical examination or available imaging studies suggesting rapid disease progression of covid-19. signs or symptoms indicative of pneumonia or any other lower respiratory tract disorders, or clinically significant findings in available lung imaging studies suggestive of such disorders. need for immediate hospitalization, oxygen supplementation or mechanical ventilation. obstructive airway diseases, including chronic obstructive pulmonary disease (copd) and asthma, or other respiratory disease that could exacerbate independent of covid-19. use of remdesivir, chloroquine, hydroxychloroquine, convalescent plasma, other monoclonal antibody therapies, include regen-cov (casirivimab and imdevimab), bamlanivimab (plus etesevimab), dexamethasone, ivermectin, baricitinib, and other janus kinase inhibitors, bruton's tyrosine kinase inhibitors, tocilizumab (and other interleukin-6 inhibitors) and any other therapy with eua or approval and other investigational agents for covid-19. patients who are participating in other clinical trials. history of conditions associated with immunocompromise, or treatments known to affect the immune system, including but not limited to oral or intravenous corticosteroids, alkylating drugs, antimetabolites, cytotoxic drugs, other chemotherapy, radiation, immune-modulating biologics, within 30 days of screening. barium enemas within the last 30 days. taking otc or prescribed medicine which has compound as active ingredient. any unstable or uncontrolled medical illnesses such as neurological disorders, cardiovascular disorders, diabetes, hepatic or renal disorders that per the investigator would intervene with the study conduct or study results interpretation. any other medical, psychiatric, or social condition or occupational or other responsibility that in the judgment of the investigator would interfere with or serve as a contraindication to protocol adherence, assessment of safety, or a patient's ability to give informed consent or respond to the study procedures or questions during the personal visits or the video calls. high-risk individuals are those who meet at least one of the following criteria: aged ≥ 65 years body mass index (bmi) > 30 pregnancy chronic kidney disease diabetes immunosuppressive disease or immunosuppressive treatment cardiovascular disease (including congenital heart disease) or hypertension chronic lung diseases (for example, chronic obstructive pulmonary disease, asthma [moderate-to-severe], interstitial lung disease, cystic fibrosis and pulmonary hypertension) sickle cell disease neurodevelopmental disorders (for example, cerebral palsy) or other conditions that confer medical complexity (for example, genetic or metabolic syndromes and severe congenital anomalies) having a medical-related technological dependence (for example, tracheostomy, gastrostomy, or positive pressure ventilation [not related to covid-19] exclusion is not limited to the medical conditions or factors listed above. the investigators have to consider the benefit-risk for an individual patient to determine other medical conditions or factors (for example, overweight, race or ethnicity) may also place individual patients at high risk for progression to severe covid-19 and be excluded.

patient is either asymptomatic or with baseline severity of moderate, sever, or critical covid-19. pregnant or lactating women. patients with shortness of breath at rest. findings on physical examination or available imaging studies suggesting rapid disease progression of covid-19. signs or symptoms indicative of pneumonia or any other lower respiratory tract disorders, or clinically significant findings in available lung imaging studies suggestive of such disorders. need for immediate hospitalization, oxygen supplementation or mechanical ventilation. obstructive airway diseases, including chronic obstructive pulmonary disease (copd) and asthma, or other respiratory disease that could exacerbate independent of covid-19. use of remdesivir, chloroquine, hydroxychloroquine, convalescent plasma, other monoclonal antibody therapies, include regen-cov (casirivimab and imdevimab), bamlanivimab (plus etesevimab), dexamethasone, ivermectin, baricitinib, and other janus kinase inhibitors, bruton's tyrosine kinase inhibitors, tocilizumab (and other interleukin-6 inhibitors) and any other therapy with eua or approval and other investigational agents for covid-19. patients who are participating in other clinical trials. history of conditions associated with immunocompromise, or treatments known to affect the immune system, including but not limited to oral or intravenous corticosteroids, alkylating drugs, antimetabolites, cytotoxic drugs, other chemotherapy, radiation, immune-modulating biologics, within 30 days of screening. barium enemas within the last 30 days. taking otc or prescribed medicine which has tannic acid as active ingredient. any unstable or uncontrolled medical illnesses such as neurological disorders, cardiovascular disorders, diabetes, hepatic or renal disorders that per the investigator would intervene with the study conduct or study results interpretation. any other medical, psychiatric, or social condition or occupational or other responsibility that in the judgment of the investigator would interfere with or serve as a contraindication to protocol adherence, assessment of safety, or a patient's ability to give informed consent or respond to the study procedures or questions during the personal visits or the video calls. high-risk individuals are those who meet at least one of the following criteria: aged ≥ 65 years body mass index (bmi) > 30 pregnancy chronic kidney disease diabetes immunosuppressive disease or immunosuppressive treatment cardiovascular disease (including congenital heart disease) or hypertension chronic lung diseases (for example, chronic obstructive pulmonary disease, asthma [moderate-to-severe], interstitial lung disease, cystic fibrosis and pulmonary hypertension) sickle cell disease neurodevelopmental disorders (for example, cerebral palsy) or other conditions that confer medical complexity (for example, genetic or metabolic syndromes and severe congenital anomalies) having a medical-related technological dependence (for example, tracheostomy, gastrostomy, or positive pressure ventilation [not related to covid-19] exclusion is not limited to the medical conditions or factors listed above. the investigators have to consider the benefit-risk for an individual patient to determine other medical conditions or factors (for example, overweight, race or ethnicity) may also place individual patients at high risk for progression to severe covid-19 and be excluded.

patient is either asymptomatic or with baseline severity of moderate, sever, or critical covid-19. pregnant or lactating women. patients with shortness of breath at rest. findings on physical examination or available imaging studies suggesting rapid disease progression of covid-19. signs or symptoms indicative of pneumonia or any other lower respiratory tract disorders, or clinically significant findings in available lung imaging studies suggestive of such disorders. need for immediate hospitalization, oxygen supplementation or mechanical ventilation. obstructive airway diseases, including chronic obstructive pulmonary disease (copd) and asthma, or other respiratory disease that could exacerbate independent of covid-19. use of remdesivir, chloroquine, hydroxychloroquine, convalescent plasma, other monoclonal antibody therapies, include regen-cov (casirivimab and imdevimab), bamlanivimab (plus etesevimab), dexamethasone, ivermectin, baricitinib, and other janus kinase inhibitors, bruton's tyrosine kinase inhibitors, tocilizumab (and other interleukin-6 inhibitors) and any other therapy with eua or approval and other investigational agents for covid-19. patients who are participating in other clinical trials. history of conditions associated with immunocompromise, or treatments known to affect the immune system, including but not limited to oral or intravenous corticosteroids, alkylating drugs, antimetabolites, cytotoxic drugs, other chemotherapy, radiation, immune-modulating biologics, within 30 days of screening. barium enemas within the last 30 days. taking otc or prescribed medicine which has tannic acid as active ingredient. any unstable or uncontrolled medical illnesses such as neurological disorders, cardiovascular disorders, diabetes, hepatic or renal disorders that per the investigator would intervene with the study conduct or study results interpretation. any other medical, psychiatric, or social condition or occupational or other responsibility that in the judgment of the investigator would interfere with or serve as a contraindication to protocol adherence, assessment of safety, or a patient's ability to give informed consent or respond to the study procedures or questions during the personal visits or the video calls. high-risk individuals are those who meet at least one of the following criteria: aged ≥ 65 years body mass index (bmi) > 30 pregnancy chronic kidney disease diabetes immunosuppressive disease or immunosuppressive treatment cardiovascular disease (including congenital heart disease) or hypertension chronic lung diseases (for example, chronic obstructive pulmonary disease, asthma [moderate-to-severe], interstitial lung disease, cystic fibrosis and pulmonary hypertension) sickle cell disease neurodevelopmental disorders (for example, cerebral palsy) or other conditions that confer medical complexity (for example, genetic or metabolic syndromes and severe congenital anomalies) having a medical-related technological dependence (for example, tracheostomy, gastrostomy, or positive pressure ventilation [not related to covid-19] exclusion is not limited to the medical conditions or factors listed above. the investigators have to consider the benefit-risk for an individual patient to determine other medical conditions or factors (for example, overweight, race or ethnicity) may also place individual patients at high risk for progression to severe covid-19 and be excluded.

1. patient is either asymptomatic or with baseline severity of moderate, sever, or critical covid-19. 2. pregnant or lactating women. 3. patients with shortness of breath at rest. 4. findings on physical examination or available imaging studies suggesting rapid disease progression of covid-19. 5. signs or symptoms indicative of pneumonia or any other lower respiratory tract disorders, or clinically significant findings in available lung imaging studies suggestive of such disorders. 6. need for immediate hospitalization, oxygen supplementation or mechanical ventilation. 7. obstructive airway diseases, including chronic obstructive pulmonary disease (copd) and asthma, or other respiratory disease that could exacerbate independent of covid-19. 8. use of remdesivir, chloroquine, hydroxychloroquine, convalescent plasma, other monoclonal antibody therapies, include regen-cov (casirivimab and imdevimab), bamlanivimab (plus etesevimab), dexamethasone, ivermectin, baricitinib, and other janus kinase inhibitors, bruton's tyrosine kinase inhibitors, tocilizumab (and other interleukin-6 inhibitors) and any other therapy with eua or approval and other investigational agents for covid-19. 9. patients who are participating in other clinical trials. 10. history of conditions associated with immunocompromise, or treatments known to affect the immune system, including but not limited to oral or intravenous corticosteroids, alkylating drugs, antimetabolites, cytotoxic drugs, other chemotherapy, radiation, immune-modulating biologics, within 30 days of screening. 11. barium enemas within the last 30 days. 12. taking otc or prescribed medicine which has tannic acid as active ingredient. 13. any unstable or uncontrolled medical illnesses such as neurological disorders, cardiovascular disorders, diabetes, hepatic or renal disorders that per the investigator would intervene with the study conduct or study results interpretation. 14. any other medical, psychiatric, or social condition or occupational or other responsibility that in the judgment of the investigator would interfere with or serve as a contraindication to protocol adherence, assessment of safety, or a patient's ability to give informed consent or respond to the study procedures or questions during the personal visits or the video calls. 15. high-risk individuals are those who meet at least one of the following criteria: 1. aged ≥ 65 years 2. body mass index (bmi) > 30 3. pregnancy 4. chronic kidney disease 5. diabetes 6. immunosuppressive disease or immunosuppressive treatment 7. cardiovascular disease (including congenital heart disease) or hypertension 8. chronic lung diseases (for example, chronic obstructive pulmonary disease, asthma [moderate-to-severe], interstitial lung disease, cystic fibrosis and pulmonary hypertension) 9. sickle cell disease 10. neurodevelopmental disorders (for example, cerebral palsy) or other conditions that confer medical complexity (for example, genetic or metabolic syndromes and severe congenital anomalies) 11. having a medical-related technological dependence (for example, tracheostomy, gastrostomy, or positive pressure ventilation [not related to covid-19] 12. exclusion is not limited to the medical conditions or factors listed above. the investigators have to consider the benefit-risk for an individual patient to determine other medical conditions or factors (for example, overweight, race or ethnicity) may also place individual patients at high risk for progression to severe covid-19 and be excluded.

1. patient is either asymptomatic or with baseline severity of moderate, sever, or critical covid-19. 2. pregnant or lactating women. 3. patients with shortness of breath at rest. 4. findings on physical examination or available imaging studies suggesting rapid disease progression of covid-19. 5. signs or symptoms indicative of pneumonia or any other lower respiratory tract disorders, or clinically significant findings in available lung imaging studies suggestive of such disorders. 6. need for immediate hospitalization, oxygen supplementation or mechanical ventilation. 7. obstructive airway diseases, including chronic obstructive pulmonary disease (copd) and asthma, or other respiratory disease that could exacerbate independent of covid-19. 8. use of remdesivir, chloroquine, hydroxychloroquine, convalescent plasma, other monoclonal antibody therapies, include regen-cov (casirivimab and imdevimab), bamlanivimab (plus etesevimab), dexamethasone, ivermectin, baricitinib, and other janus kinase inhibitors, bruton's tyrosine kinase inhibitors, tocilizumab (and other interleukin-6 inhibitors) and any other therapy with eua or approval and other investigational agents for covid-19. 9. patients who are participating in other clinical trials. 10. history of conditions associated with immunocompromise, or treatments known to affect the immune system, including but not limited to oral or intravenous corticosteroids, alkylating drugs, antimetabolites, cytotoxic drugs, other chemotherapy, radiation, immune-modulating biologics, within 30 days of screening. 11. barium enemas within the last 30 days. 12. taking otc or prescribed medicine which has tannic acid as active ingredient. 13. any unstable or uncontrolled medical illnesses such as neurological disorders, cardiovascular disorders, diabetes, hepatic or renal disorders that per the investigator would intervene with the study conduct or study results interpretation. 14. any other medical, psychiatric, or social condition or occupational or other responsibility that in the judgment of the investigator would interfere with or serve as a contraindication to protocol adherence, assessment of safety, or a patient's ability to give informed consent or respond to the study procedures or questions during the personal visits or the video calls. 15. high-risk individuals are those who meet at least one of the following criteria: 1. aged ≥ 65 years 2. body mass index (bmi) > 30 3. pregnancy 4. chronic kidney disease 5. diabetes 6. immunosuppressive disease or immunosuppressive treatment 7. cardiovascular disease (including congenital heart disease) or hypertension 8. chronic lung diseases (for example, chronic obstructive pulmonary disease, asthma [moderate-to-severe], interstitial lung disease, cystic fibrosis and pulmonary hypertension) 9. sickle cell disease 10. neurodevelopmental disorders (for example, cerebral palsy) or other conditions that confer medical complexity (for example, genetic or metabolic syndromes and severe congenital anomalies) 11. having a medical-related technological dependence (for example, tracheostomy, gastrostomy, or positive pressure ventilation [not related to covid-19] 12. exclusion is not limited to the medical conditions or factors listed above. the investigators have to consider the benefit-risk for an individual patient to determine other medical conditions or factors (for example, overweight, race or ethnicity) may also place individual patients at high risk for progression to severe covid-19 and be excluded.

1. patient is either asymptomatic or with baseline severity of moderate, sever, or critical covid-19. 2. pregnant or lactating women. 3. patients with shortness of breath at rest. 4. findings on physical examination or available imaging studies suggesting rapid disease progression of covid-19. 5. signs or symptoms indicative of pneumonia or any other lower respiratory tract disorders, or clinically significant findings in available lung imaging studies suggestive of such disorders. 6. need for immediate hospitalization, oxygen supplementation or mechanical ventilation. 7. obstructive airway diseases, including chronic obstructive pulmonary disease (copd) and asthma, or other respiratory disease that could exacerbate independent of covid-19. 8. use of remdesivir, chloroquine, hydroxychloroquine, convalescent plasma, other monoclonal antibody therapies, include regen-cov (casirivimab and imdevimab), bamlanivimab (plus etesevimab), dexamethasone, ivermectin, baricitinib, and other janus kinase inhibitors, bruton's tyrosine kinase inhibitors, tocilizumab (and other interleukin-6 inhibitors) and any other therapy with eua or approval and other investigational agents for covid-19. 9. patients who are participating in other clinical trials. 10. history of conditions associated with immunocompromise, or treatments known to affect the immune system, including but not limited to oral or intravenous corticosteroids, alkylating drugs, antimetabolites, cytotoxic drugs, other chemotherapy, radiation, immune-modulating biologics, within 30 days of screening. 11. barium enemas within the last 30 days. 12. taking otc or prescribed medicine which has tannic acid as active ingredient. 13. any unstable or uncontrolled medical illnesses such as neurological disorders, cardiovascular disorders, diabetes, hepatic or renal disorders that per the investigator would intervene with the study conduct or study results interpretation. 14. any other medical, psychiatric, or social condition or occupational or other responsibility that in the judgment of the investigator would interfere with or serve as a contraindication to protocol adherence, assessment of safety, or a patient's ability to give informed consent or respond to the study procedures or questions during the personal visits or the video calls. 15. high-risk individuals are those who meet at least one of the following criteria: 1. body mass index (bmi) ≥ 35 2. chronic kidney disease 3. diabetes mellitus 4. immunocompromising condition 5. currently receiving immunosuppressive treatment 6. aged ≥ 65 years 7. aged ≥ 50 years and have: - cardiovascular disease, or - hypertension, or - chronic obstructive pulmonary disease or another chronic respiratory disease.

1. patient is either asymptomatic or with baseline severity of moderate, sever, or critical covid-19. 2. pregnant or lactating women. 3. patients with shortness of breath at rest. 4. findings on physical examination or available imaging studies suggesting rapid disease progression of covid-19. 5. signs or symptoms indicative of pneumonia or any other lower respiratory tract disorders, or clinically significant findings in available lung imaging studies suggestive of such disorders. 6. need for immediate hospitalization, oxygen supplementation or mechanical ventilation. 7. obstructive airway diseases, including chronic obstructive pulmonary disease (copd) and asthma, or other respiratory disease that could exacerbate independent of covid-19. 8. use of remdesivir, chloroquine, hydroxychloroquine, convalescent plasma, other monoclonal antibody therapies, include regen-cov (casirivimab and imdevimab), bamlanivimab (plus etesevimab), dexamethasone, ivermectin, baricitinib, and other janus kinase inhibitors, bruton's tyrosine kinase inhibitors, tocilizumab (and other interleukin-6 inhibitors) and any other therapy with eua or approval and other investigational agents for covid-19. 9. patients who are participating in other clinical trials. 10. history of conditions associated with immunocompromise, or treatments known to affect the immune system, including but not limited to oral or intravenous corticosteroids, alkylating drugs, antimetabolites, cytotoxic drugs, other chemotherapy, radiation, immune-modulating biologics, within 30 days of screening. 11. barium enemas within the last 30 days. 12. taking otc or prescribed medicine which has tannic acid as active ingredient. 13. any unstable or uncontrolled medical illnesses such as neurological disorders, cardiovascular disorders, diabetes, hepatic or renal disorders that per the investigator would intervene with the study conduct or study results interpretation. 14. any other medical, psychiatric, or social condition or occupational or other responsibility that in the judgment of the investigator would interfere with or serve as a contraindication to protocol adherence, assessment of safety, or a patient's ability to give informed consent or respond to the study procedures or questions during the personal visits or the video calls. 15. high-risk individuals are those who meet at least one of the following criteria: 1. body mass index (bmi) ≥ 35 2. chronic kidney disease 3. diabetes mellitus 4. immunocompromising condition 5. currently receiving immunosuppressive treatment 6. aged ≥ 65 years 7. aged ≥ 50 years and have: - cardiovascular disease, or - hypertension, or - chronic obstructive pulmonary disease or another chronic respiratory disease.