The COVID-19 pandemic has underscored that systems medicine depends on health systems and services that can respond to planetary health threats in scale and with speed. After 2 years of the pandemic, there are lessons learned in South Korea, from governance to risk communication for planetary health. The learning is timely because COVID-19 likely signals future ecological crises and emerging pathogens amid the climate emergency in the 21st century. By the end of March 2022, South Korea, with a population of 51.6 million, administered more COVID-19 vaccine doses per 100 people than other developed countries, including United Kingdom, Italy, Australia, Israel, Germany, and United States. In South Korea, 233.47 doses of COVID-19 vaccine were administered per 100 people, while Italy (229.48), China (229.39), Australia (217.44), the United Kingdom (211.39), Israel (194.82), and the United States (170.59) fell behind in vaccine rollout. Korea's whole-of-government approach to robust COVID-19 vaccination rollout prompted broad interest in planetary health. Notwithstanding that vaccine rollout is a complex multifactorial outcome, six salient, and often interdependent, factors are identified in this study of South Korea: (1) governance system; (2) logistic capability; (3) delivery strategy and accessibility; (4) established public health infrastructure; (5) risk communication; and (6) public cooperation and engagement. Integration of these factors can create multisectoral synergy to achieve better outcomes in vaccine rollout. The lessons from South Korea can help cultivate planetary health action in other parts of the world during the current COVID-19 pandemic, and in ecological crises in the future. [ABSTRACT FROM AUTHOR]