Patient description: A 3-day-old Asian female infant presents with jaundice that started a day ago. She was born at 38w3d of gestation, after an uncomplicated pregnancy. The family history is unremarkable. The baby is breastfed. Vital signs are reported as: axillary temperature: 36.3°C, heart rate: 154 beats/min, respiratory rate: 37 breaths/min, and blood pressure: 65/33 mm Hg. Her weight is 3.2 kg, length is 53 cm, and head circumference 36 cm. Her sclera are yellow and her body is icteric. No murmurs or any other abnormalities are detected in the heart and lung auscultation. Her liver and spleen are normal on palpation. Laboratory results are as follows: Serum total bilirubin: 21.02 mg/dL Direct bilirubin of 2.04 mg/dL AST: 37 U/L ALT: 20 U/L GGT: 745 U/L Alkaline phosphatase: 531 U/L Creatinine: 0.3 mg/dL Urea: 29 mg/dL Na: 147 mEq/L K: 4.5 mEq/L CRP: 3 mg/L Complete blood cell count within the normal range. She is diagnosed with uncomplicated neonatal jaundice that may require phototherapy.

Clinical trial eligibility criteria: eligible ages (years): 18.0-999.0,  COVID-19 Adult (≥ 18 years old) men or women, hospitalized or not hospitalized, diagnosed for SARS-CoV-2 infection by PCR, with at least one associated risk factor. Considered risk factors are Age ≥ 65 years Obesity defined as BMI ≥ 30 Recent history of uncontrolled High Blood Pressure (SBP > 150 mm Hg DBP >100 mm Hg) according to investigator Treated diabetes (type I or II) History of ischemic cardiovascular disease 2. Symptomatic patients at enrollment. Symptoms are defined as fever (body temperature ≥ 37.8 C oral/tympanic, or ≥ 38.2 C rectal) for more than 24 hours associated either with headache, sore throat, dry cough, fatigue, chest pain or choking sensation (with no associated respiratory distress), myalgia, anosmia or ageusia. 3. Patients with pulse oximetry arterial saturation ≥ 92 % on room air at enrolment. 4. Patients with the following hematological and biochemical laboratory parameters obtained within 7 days prior to Day 0 Hemoglobin above 9.0 g / dL Absolute Neutrophil Count ≥ 1000 / mm3 Platelets ≥ 100 000 mm3 Creatinine clearance ≥ 50 mL / min by the Cockcroft Gault formula  Patients with moderate or severe acute respiratory failure or requiring noninvasive ventilation or oxygen or with SpO2 < 92% or tachypnea (respiratory rate ≥ 30 breaths/min). 2. Patients treated with immunosuppressors and/or immunomodulators. 3. Engrafted patients (organ and/or hematopoietic stem cells). 4. Patients with uncontrolled auto-immune disease. 5. Patients with known or suspected active (i.e. not controlled) bacterial, viral (excluding COVID-19) or fungal infections. 6. Patients with preexisting, severe and not controlled organ failure. 7. History or active malignancy requiring chemotherapy or radiation therapy (excluding 2 years disease free survivor patients). 8. Pregnant or breast-feeding women. 9. Illicit drug or alcohol abuse or dependence that may compromise the patient's safety or adherence to the study protocol. 10. Use of any investigational or non-registered product within 3 months or within 5 half-lives preceding baseline, whichever is longer. 11. Hypersensitivity to ABX464 and/or its excipients. 12. Any condition, which in the opinion of the investigator, could compromise the patient's safety or adherence to the study protocol