1. age equal or more than 7-year-old 2. Close contact with SARS-CoV-2 index case confirmed with SARS-CoV-2 PCR 3. Contact with index case less than 72 hours before enrollment 4. Comminacability by electronic module

1. age equal or more than 7-year-old 2. Close contact with SARS-CoV-2 index case confirmed with SARS-CoV-2 PCR 3. Contact with index case less than 72 hours before enrollment 4. Comminacability by electronic module