Stop in for a cup of coffee

Vietnam did the best, out of ALL Nations. They did just have a flare up in Da Nang cause some idiot smuggled in a Chinese national with the virus. But up until then, a country with 96 Million people, only had 400 cases and NO deaths.....They locked down early in January, and now again after the Da Nang issue........Hell, I know I'm safer there than here........
How did they do that ? Total Lockdown? Enforce masks?