Did a quick search with South Korea’s use of Hydroxychloroquine....
Is Chloroquine Behind South Korea’s Super-Low Coronavirus Fatality Rate?
https://www.ccn.com/is-chloroquine-behind-south-koreas-super-low-coronavirus-fatality-rate/
https://www.reddit.com/r/China_Flu/comments/foh7yt/is_hydroxychloroquine_used_in_south_korea_to/
South Korea had an EXTENSIVE testing and contact tracing program VERY early.
They tested everything that didn’t move fast enough.
And QUARANTINED not ONLY the positives but ALSO their contacts!
SK has had mandatory mask laws as well. In public? Wear a mask!
Taiwan as well. ALTHOUGH Taiwan didn’t have the initial bolus of cases from a cult superspreader event that SK did. So Taiwan cases are VERY low.
Taiwan as well. Testing, contact tracing, MANDATORY QUARANTINE of anyone positive AND their contacts. Enforced with ankle bracelets and HUGE fines. No breaking quarantine to get an all you can eat catfish buffet there.