- healthcare worker who does not have a valid credential from the center - under 25 years of age - having been diagnosed with a positive rtpcr for covid-19 - history of febrile acute respiratory disease within the previous 12 weeks - volunteer with significant alteration from laboratory tests (standard biochemical profile and hemogram) at screening. a significant abnormality will be defined according investigator's medical judgment. - women during pregnancy or breastfeeding - female subjects of childbearing age who are sexually active during the study who do not use an effective method of family planning or do not have surgical sterilization - known allergy to green tea or egcg - known starch allergy - user of any medication or supplement containing egcg - volunteer using immunosuppressive drugs - autoimmune disease (lupus, sjögren or another), liver disease - anemia requiring treatment - having a chronic infectious disease under treatment

- healthcare worker who does not have a valid credential from the center - under 25 years of age - having been diagnosed with a positive rtpcr for covid-19 - history of febrile acute respiratory disease within the previous 12 weeks - volunteer with significant alteration from laboratory tests (standard biochemical profile and hemogram) at screening. a significant abnormality will be defined according investigator's medical judgment. - women during pregnancy or breastfeeding - female subjects of childbearing age who are sexually active during the study who do not use an effective method of family planning or do not have surgical sterilization - known allergy to green tea or egcg - known starch allergy - user of any medication or supplement containing egcg - volunteer using immunosuppressive drugs - autoimmune disease (lupus, sjögren or another), liver disease - anemia requiring treatment - having a chronic infectious disease under treatment