18 years and older, both sexes Having home contact, unmasked contact with a patient with Covid-19 confirmed by RT-PCR or clinical evidence or radiography of pneumonia and acute respiratory distress syndrome (ARDS); No clinical signs of Covid-19 (fever, cough, dyspnea, shortness of breath, sore throat, extreme tiredness, digestive problems); No chronic respiratory problems or other illnesses that are mistaken for symptoms of COVID-19

18 years and older, both sexes Having home contact, unmasked contact with a patient with Covid-19 confirmed by RT-PCR or clinical evidence or radiography of pneumonia and acute respiratory distress syndrome (ARDS); No clinical signs of Covid-19 (fever, cough, dyspnea, shortness of breath, sore throat, extreme tiredness, digestive problems); No chronic respiratory problems or other illnesses that are mistaken for symptoms of COVID-19