Fig. 1

Cumulative cases and rate of COVID-19 infection in Korea according to age groups. By the end of January 2022, the Omicron variant had become the predominant strain, accounting for nearly 100% of cases in South Korea. Subsequently, an explosive increase in confirmed cases has occurred since 2022, especially in children. The cumulative number of confirmed COVID-19 cases in Korea is shown for different age groups, represented by varying shades, corresponding to the values on the left axis. The curved line graphs depict the cumulative incidence rate of cases per 100,000 populations in Korea, corresponding to the values on the right axis. The age group of 0–9 years exhibited the highest incidence rate, followed by those aged 10–19 years. The empty arrows indicate the period when each dominant variant emerged. The arrows at the top represent each case, based on their time of presentation in this study