inclusion criteria: * patients diagnosed as mild to moderate covid-19 infection with positive pcr test and symptoms (ct \< 35) * parents and patients comprehend and welling to participate in this study. * agree to the collection of nasal swabs per day as protocol.

inclusion criteria: * patients diagnosed as mild to moderate covid-19 infection with positive pcr test and symptoms (ct \< 35) * parents and patients comprehend and welling to participate in this study. * agree to the collection of nasal swabs per day as protocol.

inclusion criteria: patients diagnosed as mild to moderate covid-19 infection with positive pcr test and symptoms (ct < 35) parents and patients comprehend and welling to participate in this study. agree to the collection of nasal swabs per day as protocol.

inclusion criteria: patients diagnosed as mild to moderate covid-19 infection with positive pcr test and symptoms (ct < 35) parents and patients comprehend and welling to participate in this study. agree to the collection of nasal swabs per day as protocol.