Efficacy and Safety of Nitazoxanide for Post Exposure Prophylaxis of COVID-19

Inclusion Criteria: * Informed consent from patient or legal representative. * Subject of both genders (male and female not pregnant and not breastfeeding) aged 18 years or over; * Subject that lives in a vulnerable community; * Subject that were in direct contact with confirmed cases of SARS-CoV-2 infection, as they live or work directly with index patients; * Not showing symptoms compatible with COVID-19 and and that do not have a positive RT-PCR test in a nasopharyngeal swab sample before randomization; * Participant capable of understanding and fulfilling all activities planned for the study; * In use of an acceptable method of contraception throughout the study. Exclusion Criteria: * Participating in another RCT in the past 12 months; * Positive PCR result for COVID-19 during screening; * History of infection confirmed by SARS-CoV-2; * Present symptoms suggestive of SARS-CoV-2 infection; * Presence of comorbidities, which have a contraindication to the use of the study product, not being restricted to: * HIV or HTLV virus infection; * Chronic hepatitis C (HCV) treated with direct antiviral drugs; * Liver failure; * Severe renal failure, including dialysis; * Present hypersensitivity to the study product (nitazoxanide), as well as to related compounds; * Concomitant administration of drugs that may interact with the product under study (nitazoxanide); * Participants who underwent treatment with antivirals and / or antiparasitic drugs in the last 30 days; * Subject in antineoplastic treatment with chemotherapy or radiation therapy; * Subject with severe autoimmune diseases in immunosuppression; * Transplanted participants; * Pregnant or lactating women; * Any other clinical condition that is deemed by the Investigator to be an imminent risk to the health and life of the subject.