That's the most effective way to prevent your household, neighborhood, city, state, or country from infection....close down the borders immediately.

When the government refused at first to close the border with mainland China, more than 7,000 medical workers went on an unprecedented strike, demanding border closures and PPE for hospital workers.
Some of the signals to the government were decidedly more confrontational. Through Telegram channels, “anti-epidemic actions” were threatened if the government did not respond to the virus by closing down borders. Explosives were discovered at border checkpoints between mainland China and Hong Kong, and flaming objects were thrown at the train tracks connecting the two countries. When the government hastily set up quarantine centers in dense neighborhoods without consulting the people who lived nearby, Molotov cocktails engulfed their (empty) lobbies,