Brief Epidemiological Consideration on the COVID-19 Pandemic

Three years have passed since the first case of coro-navirus disease 2019 (COVID-19) caused by the novel coronavirus, severe acute respiratory syndrome co-ronavirus 2 (SARS-CoV-2). Although the pandemic has slowed down gradually, the situation is not yet stable. Since COVID-19 has spread mainly in devel-oped European and American countries, it is consid-ered to be said a peculiar infectious disease. It has a significant impact on medical systems in developed countries in across the globe. In the past three years, the COVID-19 epidemic has changed gradually, both globally and regionally.