It wasn't looking good for South Korea in mid-February. The nation had the world's second highest number of coronavirus cases after China. But thanks to early preparations, and a robust public health response based around extensive testing and tech-powered contact tracing, the nation's tally of infections has been kept to just 10,765. More impressive still, no major lockdown or restrictions on movement have been imposed, save a few scattered curfews. On Apr. 15, some 29 million people turned up to vote in parliamentary elections - yet no known infections arose, thanks to strict social distancing at the polls. On Wednesday, South Korea had zero local infections for the first time since the outbreak was first recorded 72 days previously. South Korea's health and welfare minister Park Neung-hoo explained to TIME exactly how his nation engineered such a remarkable turnaround. "Instead of physical lockdown, we fought the virus through an epidemiological approach such as wide diagnostic testing and isolation of contacts, while encouraging people's voluntary cooperation for social distancing," [he said]. "We believed this was more effective than forcible measures and indeed it paid off. The key is whether we are able to keep COVID-19 cases within our medical system's capacity to treat patients. In Korea, we set strict standards and regularly evaluate how patient numbers match our medical capacity, allowing us balance the two pressing needs [of public health and economy]."