inclusion criteria: - sar-cov2 detected by pcr from np swab - asymptomatic or upper respiratory symptoms such as runny noses - no history of fever or oral temp <37.8 degree celsius - informed consent obtained

inclusion criteria: - sar-cov2 detected by pcr from np swab - asymptomatic or upper respiratory symptoms such as runny noses - no history of fever or oral temp <37.8 degree celsius - informed consent obtained