Clinical Research Directory

Inclusion Criteria: * Volunteer healthcare worker with any valid credential of the center * 25 years old and over * Not having been diagnosed with COVID-19 * A healthy individual as per investigator's judgment or stating stable non-transmissible chronic disease without hospitalization in the last year, without change of medications or addition of medications to treat chronic illnesses in the last 3 months. * No pregnancy or breastfeeding * Female subjects of childbearing potential using an effective family planning method or surgical sterilization or not sexually active during the study * Do not drink more than 300 ml of tea a day * Do not take supplements or products containing EGCG during the study * Being able to set aside time each day to complete the study questionnaires * Being able to read and understand the informed consent form before the study Exclusion Criteria: * 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