Although the epidemiology of Coronavirus Disease 2019 (COVID-19) has considerably changed over time, displaying a substantial decline in severe forms of illness and death rate [1], a recent claim by the World Health Organization (WHO) emphasized that the pandemic has not yet passed, and COVID-19 must still be considered a public health emergency of international concern [2]. The persistence of the pandemic gives us the opportunity to analyze and briefly discuss the most important reasons for the biological success that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has exhibited during the first 3 years of the pandemic, since an accurate understanding of these mechanisms may provide vital clues for facing a future pandemic sustained by new variants of concern or similar pathogens.
