Pre-Exposure Prophylaxis With Hydroxychloroquine for High-Risk Healthcare Workers During the COVID-19 Pandemic

Inclusion Criteria: * Age ≥ 18 years * Negative PCR and negative serology on day 0 * Healthcare worker at any of the trial sites * Female participants: negative for pregnancy test * Willing to participate in the study * Able to sign the informed consent form Exclusion Criteria: * Age \<18 years * Pregnancy or breastfeeding * Ongoing antiviral or antiretroviral treatment or HIV positive * Ongoing anti-inflammatory treatment (corticosteroids) * Ongoing or previous (1 month) chloroquine or hydroxychloroquine treatment * Confirmed case of SARS-CoV-2 infection (positive PCR) at day 0 * Positive serology for SARS-CoV-1 infection at day 0 * Impossibility of signing the informed consent form * Rejection of participation * Working less than 3 days a week in the Hospital Clinic of Barcelona. * Any contraindication for hydroxychloroquine treatment: * Hydroxychloroquine hypersensitivity or 4-aminoquinoline hypersensitivity * Retinopathy, visual field or visual acuity disturbances * QT prolongation, bradycardia (\<50bpm), ventricular tachycardia, other arrhythmias, as determined on day 0 ECG or medical history * Potassium \< 3 mEq/L or AST or ALT \> 5 upper normal limit, as determined on day 0 blood test * Previous myocardial infarction * Myasthenia gravis * Porphyria * Glomerular clearance \< 10ml/min * Previous history of severe hypoglycaemia * Ongoing treatment with antimalarials, antiarrhythmic, tricyclic antidepressants, selective serotonin reuptake inhibitors, natalizumab, quinolones, macrolides, agalsidase alfa and beta.