Inclusion Criteria:  Hospital admitted patients with severe COVID-19 pneumonia (Individuals who have SpO2 <94% on room air at sea level, a ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PaO2/FiO2) <300 mm Hg, respiratory frequency >30 breaths/min, or lung infiltrates >50%). Confirmed diagnosis of Covid-19 through qualitative polymerase-reverse transcriptase (qRT-PCR -GeneDX Co, Ltd o similar) or antigen rapid test.  Patients who received tocilizumab or shared the same indication but did not received it (same period of time or previous close period) that:  Progress in the requirement of supplemental oxygen (over 3L/m) and/or use of non-rebreathing mask with 8L/m or more to mantain a Sp02>= 94%.  AND  * Active inflammatory state defined as persistent fever > 38°C (defined as 2 or more measurements in a 24-hour period from hospital admission) despite the use of dexamethasone in the previous 48 hours OR C reactive Protein > 50 mg /dL OR D Dimer > 1000 ng/mL.  Exclusion Criteria:  Asymptomatic, mild or moderate COVID-19 disease. Patients with some type of immunosupression (HIV, use of immunomodulatory drugs, organ-trasplant receipt patients) Pregnant or breast-feeding Patients with augmented risk of bowel perforation (history of diverticulitis or bowel surgery in the three months prior to the study entrance date) Known severe allergic reactions to TCZ Suspected active bacterial, fungal, viral, or other infection (besides COVID-19) Alanine aminotransferase (ALT) or aspartate aminotransferase (AST) > 5 x upper limit of normal (ULN) at screening Absolute neutrophil count (ANC) < 1000/mL at screening Platelet count < 50,000/mL at screening Positive Hepatitis B Surface (HbS) antigen Procalcitonine > 0,5 ng/mL Day of symptom onset before day 7 or after day 12 Patients with dementia Patients non eligible to progress to mechanical ventilation because of frailty/comorbidites according to medical decision.