By THE NATION
The doctor said through his social media account that the a safe zone is always a place which is free from a disease for two times the incubation period. The concept was used in the time of Sars, Mers and also Ebola.
For example in the case of Sars, a safe zone is an area where a Sars case is not found for 20 days, since the incubation period is 10 days.
In the case of Covid-19, the safe zone must be areas where Covid-19 is not found for 28 days, since its incubation period is 14 days.