Coronavirus disease 2019 (COVID-19) is the third severe acute respiratory disease of the 21st century and the most aggressive global pandemic to date. The whole population has been susceptible to the disease, particularly the emerging variants of the virus. The core pathophysiological mechanism is viral sepsis that can lead to the respiratory tract disorders and even systemic disorders such as cytokine release syndrome, thrombosis, abnormal angiogenesis, and multiple organ dysfunction. Despite only few licensed treatments to date, rapid advances have been made in exploring the effectiveness and safety of pharmacological interventions and vaccines. However, three pillars of preventative and control measures - proactive contact tracing, wearing facial masks, and social distancing - are essential to combat the ongoing pandemic. As the number of patients recovering from COVID-19 rapidly increases, the world has entered the era of caring for patients during the convalescence phase. This phase still represents a largely unmet medical need globally.