The
COVID-19 problem has been ongoing worldwide, and cause clustering in various
facilities. Authors have managed a nursing home with 90 residents and 50
staffs, where no COVID-19 cases exist for 3 years. Three important measures may
contribute, where i) thorough ventilation; air conditioning throughout the
year, ii) routine antigen exam; tests are conducted frequently during higher
risk period, and twice a month even almost no risk period, and iii) thoroughly
stop coming to work when feeling unwell; the person is not responsible at all,
and resting at home is the best way to prevent clusters and save all people.