Background The epidemiology of coronavirus disease 2019 (COVID-19) has changed continuously throughout the pandemic. Methods We analyzed changes in the incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection according to the age group in South Korea from February 2020 to December 2021. Results Since the COVID-19 pandemic, the incidence among adults aged ≥ 18 years was higher than all the other age groups in 2020; however, a shift toward younger ages occurred in June 2021. In addition, we found significant changes in epidemiology after the introduction of SARS-CoV-2 vaccines in adults aged ≥ 18 and children 12–17 years. Until recently, children were not regarded as the drive for the pandemic; however, children aged 5–11 and 0–4 years had the highest incidence among all the age groups. Conclusion Therefore, policies for clinical support for an increase in COVID-19 cases among young children and age-specific preventive measures are needed. Graphical Abstract
【저자키워드】 COVID-19, Vaccine, Korea, Child, Adolescent,