With winter approaching, it’s time to talk about the optimal Covid-19 strategy again – and for that, we need to look once more at what’s happening in South Korea. It has vaccinated 79.2% of its population with two doses, and, if it continues administering 220,000 doses a day, will have covered almost 90% of its population by the end of the year. Compare this to the UK, where 68.6% of the population has received two doses, and the US, where this figure is at 58%. If we compare deaths, the numbers are even more shocking. South Korea has suffered only 3,137 from a population of 51.8 million. For the UK, the corresponding figures are 142,945 deaths from a population of 67.2 million, while in the US there have been 783,575 deaths from a population of 329.5 million. In addition, in the first quarter of 2021, South Korea became one of the first high-income countries to see its economy recover to pre-pandemic levels, after it managed to only experience a 1% contraction in GDP in 2020 (the second-best performance behind China). How did South Korea escape the pandemic relatively unaffected economically, with deaths at such low levels, while now vaccinating at such a high level that it has protected itself from future waves of illness and harsh lockdowns? That’s the question we should all be asking, and a clear vindication of the “zero Covid” approach as the optimal short-term strategy. South Korea has attracted a lot of attention for following a specific “east Asian” playbook of maximum suppression: I wrote about this in March 2020, pushing countries to follow the “Seoul model”, and again in May 2020, laying out the key components of the strategy. This involved finding Covid cases through mass testing, tracing contacts, and supporting isolation to ensure chains of transmission were broken. This was supported by strict travel restrictions to prevent new cases being imported, and strong messaging to the public about wearing masks in public spaces, and the dangers of a new infectious disease. The government worked to protect its people (not to enrich its own interests) and the response was pre-emptive, organised like clockwork, and efficiently delivered. South Korea had experienced Mers, another coronavirus, and understood the dangers of a hands-off approach. As a short-term strategy, maximum suppression helped buy time for scientists to get to work, and therefore find a sustainable exit from the crisis. In 2020, it allowed numerous vaccines to be developed and approved, followed in 2021 by several promising therapeutics that keep people out of hospital and safer from descending into severe disease. Once these new tools became available, the medium- to longer-term strategy evolved, too. The next step after zero Covid has been a focus on vaccinating the population to a high threshold, and acquiring antivirals that can be given in outpatient care to keep the burden off healthcare services. The pivot from maximum suppression to mass vaccination was a rational and logical shift to achieve a successful transition out of the pandemic. The countries that followed this model – South Korea, Taiwan, and even their Pacific neighbours, Australia and New Zealand – are now managing to vaccinate their populations and protect both lives and livelihoods. Each person that wasn’t infected in 2020, thanks to these maximum suppression strategies, could live on into the phase we are now in: where vaccines and therapeutics are allowing people who catch Covid to survive, when they might otherwise have died. Mistakes have clearly been made in both the UK and US – in particular, a cynical fatalism that no scientific solution would emerge, that mass infection was inevitable and that there was little to be learned from other parts of the world. It’s the grim worldview that underscores the infamous words Boris Johnson is alleged to have said to his staff last year: “Let the bodies pile high.” It is never too late to learn lessons from countries such as South Korea, which pursued maximum suppression, and succeeded. Yes, there will be future outbreaks of pathogens with pandemic potential, and we are now working to prepare for these. Over the past six months I’ve been vice-chair of a National Academies of Sciences, Engineering, and Medicine (Nasem) commission advising the US government on how to prepare for the next pandemic, most likely flu. Our report is out next week, and looks at how we can move quickly from identifying new viruses, sequencing them, and getting testing, treatments and vaccines deployed within 100 days. A universal flu vaccine and pan-coronavirus vaccine are both on the horizon, and would mean moving even faster than that time period. Within those 100 days, all countries would hopefully focus on maximum suppression and follow the South Korean playbook of buying time for the scientific cavalry. Most of the deaths in the US and UK were preventable, and so was the economic contraction. In the UK we spent a long time debating what to do at the start of the pandemic, but it was always clear what had to be done: stop people becoming infected, without locking everyone in their homes. The challenge was how to do it, and to learn quickly from other countries that were managing to keep their economies open while keeping infection numbers low. Debate for the sake of debate costs lives and is divisive and confusing. Let us hope that next time we can agree on what needs to be done, and just get on with doing it – and that we have leaders who care enough about their people to make the effort. Prof Devi Sridhar is chair of global public health at the University of Edinburgh