All subjects must be aged ≥18 years, male or female, must be willing and able to give informed consent and must not have any contraindications to take hydroxychloroquine (intolerance or previous toxicity for hydroxychloroquine/chloroquine, bradycardia or reduction in heart rhythm with arrhythmia, ischemic heart disease, retinopathy, congestive heart failure with use of diuretics, favism or glucose-6-phosphate dehydrogenase (G6PD) deficiency, diabetes type 1, major comorbidities such as advanced chronic kidney disease or dialysis therapy, known history of ventricular arrhythmia, any oncologic/hematologic malignancy, severe neurological and mental illness, current use of medications with known significant drug-drug interactions, and known prolonged QT syndrome or current use of drugs with known QT prolongation).