inclusion criteria: 1. healthcare workers voluntarily deciding to participate in the study 2. understanding the study purpose 3. having between 18 and 70 years old 4. having a high transmission risk for covid-19. physicians, nurses, lab technicians, physical therapists, or cleaning personnel working at covid-19 areas, hospital emergency areas, or intensive care units from healthcare institutions with the direct assistance of patients with covid-19. 5. not having a prior diagnosis of sars-cov-2 infection (covid-19) 6. having a negative igm/igg antibodies test for sars-cov-2 (covid-19) prior to study entry 7. negative pregnancy test for childbearing age women within 7 days prior to study entry. 8. childbearing age males and females should comply with the use of a proven contraceptive method (double barrier methods, oral contraceptives or contraceptive hormone implants) during the course of the study and at least one month after study completion.

inclusion criteria: 1. healthcare workers voluntarily deciding to participate in the study 2. understanding the study purpose 3. having between 18 and 70 years old 4. having a high transmission risk for covid-19. physicians, nurses, lab technicians, physical therapists, or cleaning personnel working at covid-19 areas, hospital emergency areas, or intensive care units from healthcare institutions with the direct assistance of patients with covid-19. 5. not having a prior diagnosis of sars-cov-2 infection (covid-19) 6. having a negative igm/igg antibodies test for sars-cov-2 (covid-19) prior to study entry 7. negative pregnancy test for childbearing age women within 7 days prior to study entry. 8. childbearing age males and females should comply with the use of a proven contraceptive method (double barrier methods, oral contraceptives or contraceptive hormone implants) during the course of the study and at least one month after study completion.

inclusion criteria: healthcare workers voluntarily deciding to participate in the study understanding the study purpose having between 18 and 70 years old having a high transmission risk for covid-19. physicians, nurses, lab technicians, physical therapists, or cleaning personnel working at covid-19 areas, hospital emergency areas, or intensive care units from healthcare institutions with the direct assistance of patients with covid-19. not having a prior diagnosis of sars-cov-2 infection (covid-19) having a negative igm/igg antibodies test for sars-cov-2 (covid-19) prior to study entry negative pregnancy test for childbearing age women within 7 days prior to study entry. childbearing age males and females should comply with the use of a proven contraceptive method (double barrier methods, oral contraceptives or contraceptive hormone implants) during the course of the study and at least one month after study completion.

inclusion criteria: healthcare workers voluntarily deciding to participate in the study understanding the study purpose having between 18 and 70 years old having a high transmission risk for covid-19. physicians, nurses, lab technicians, physical therapists, or cleaning personnel working at covid-19 areas, hospital emergency areas, or intensive care units from healthcare institutions with the direct assistance of patients with covid-19. not having a prior diagnosis of sars-cov-2 infection (covid-19) having a negative igm/igg antibodies test for sars-cov-2 (covid-19) prior to study entry negative pregnancy test for childbearing age women within 7 days prior to study entry. childbearing age males and females should comply with the use of a proven contraceptive method (double barrier methods, oral contraceptives or contraceptive hormone implants) during the course of the study and at least one month after study completion.

inclusion criteria: 1. healthcare workers voluntarily deciding to participate in the study 2. understanding the study purpose 3. having between 18 and 70 years old 4. having a high transmission risk for covid-19. physicians, nurses, lab technicians, physical therapists, or cleaning personnel working at covid-19 areas, hospital emergency areas, or intensive care units from healthcare institutions with the direct assistance of patients with covid-19. 5. not having a prior diagnosis of sars-cov-2 infection (covid-19) 6. having a negative igm/igg antibodies test for sars-cov-2 (covid-19) prior to study entry 7. negative pregnancy test for childbearing age women within 7 days prior to study entry. 8. childbearing age males and females should comply with the use of a proven contraceptive method (double barrier methods, oral contraceptives or contraceptive hormone implants) during the course of the study and at least one month after study completion.

inclusion criteria: 1. healthcare workers voluntarily deciding to participate in the study 2. understanding the study purpose 3. having between 18 and 70 years old 4. having a high transmission risk for covid-19. physicians, nurses, lab technicians, physical therapists, or cleaning personnel working at covid-19 areas, hospital emergency areas, or intensive care units from healthcare institutions with the direct assistance of patients with covid-19. 5. not having a prior diagnosis of sars-cov-2 infection (covid-19) 6. having a negative igm/igg antibodies test for sars-cov-2 (covid-19) prior to study entry 7. negative pregnancy test for childbearing age women within 7 days prior to study entry. 8. childbearing age males and females should comply with the use of a proven contraceptive method (double barrier methods, oral contraceptives or contraceptive hormone implants) during the course of the study and at least one month after study completion.