“…The mortality rate of COVID-19 varied greatly between countries, but it may reach approximately 10 % in European countries (Omer, Malani, & Del Rio, 2020). Yet, the case fatality rate may reach 20 % among people aged over 80 years (Onder, Rezza, & Brusaferro, 2020), or with multimorbidity (Jordan, Adab, & Cheng, 2020;Logar, 2020;Niu et al, 2020). Until now, no effective therapeutics is available, so public health approach remained to be the most important strategy for COVID-19 control, including lockdown of communities or even cities, face mask ordinances, quarantine, and cordon sanitaire, and so on (Hartley & Perencevich, 2020).…”