Inclusion Criteria:  Patients ≥ 18 years of age hospitalized in the COVID-19 wards of ASST Monza - San Gerardo Hospital with positive, weakly positive or negative nasopharyngeal swabs; initially assessed at the E.R.; symptomatic or asymptomatic with indication to hospitalization. Informed consent freely granted and acquired before the start of the study.  Exclusion Criteria:  Patients with significant clinical conditions which could interfere with the study in the opinion of the researchers.