Shutting down borders helps if the virus hasn't reached your country. If it has, there's no point in banning incoming people (maybe you can stop people from le

Shutting down borders helps if the virus hasn't reached your country. If it has, there's no point in banning incoming people (maybe you can stop people from leaving so other regions don't get infected, but that's a less strong incentive). If you already have the virus in your country, the best thing you can do is slow its spreading, by banning large groups of people from congregating.