inclusion criteria: - adult healthcare workers all genders ≥ 18 to ≤ 60 years of age upon study consent. - healthcare workers (doctors and nurses) at services hospital, lahore considered work at high-risk of sars-cov-2 exposure (defined below): - healthcare workers in corona triage areas. - healthcare workers in corona isolation units. - healthcare workers in corona icus. - healthcare workers in general medical wards. - healthcare workers in general surgical wards. - healthcare workers in other units not directly dealing with suspected corona patients e.g. endocrinology department - afebrile with no constitutional symptoms. - no household contact with confirmed active sars-cov-2 infection in the last 3 weeks. - negative pcr at visit 0. - willing and able to comply with scheduled visits, treatment plan, and other study procedures. - willing to not take any other medicines especially fluoroquinolones and macrolides for the duration of study. - signed informed consent, demonstrating that the subject understands the interventions required for the study and the purpose of the study.

inclusion criteria: - adult healthcare workers all genders ≥ 18 to ≤ 60 years of age upon study consent. - healthcare workers (doctors and nurses) at services hospital, lahore considered work at high-risk of sars-cov-2 exposure (defined below): - healthcare workers in corona triage areas. - healthcare workers in corona isolation units. - healthcare workers in corona icus. - healthcare workers in general medical wards. - healthcare workers in general surgical wards. - healthcare workers in other units not directly dealing with suspected corona patients e.g. endocrinology department - afebrile with no constitutional symptoms. - no household contact with confirmed active sars-cov-2 infection in the last 3 weeks. - negative pcr at visit 0. - willing and able to comply with scheduled visits, treatment plan, and other study procedures. - willing to not take any other medicines especially fluoroquinolones and macrolides for the duration of study. - signed informed consent, demonstrating that the subject understands the interventions required for the study and the purpose of the study.