Practice and principle of traditional Chinese medicine for the prevention and treatment of COVID-19.

Traditional Chinese medicine (TCM) has played an important role in the prevention and treatment of Coronavirus disease 2019 (COVID-19) epidemic in China. The integration of Chinese and Western medicine is an important feature of Chinese COVID-19 prevention and treatment. According to a series of evidence-based studies, TCM can reduce the infection rate of severe acute respiratory syndrome coronavirus 2 in high-risk groups. For patients with mild and moderate forms of COVID-19, TCM can relieve the related signs and symptoms, shorten the period of nucleic-acid negative conversion, and reduce conversion rate to the severe form of the disease. For COVID-19 patients with severe and critical illnesses, TCM can improve inflammatory indicators and blood oxygen saturation, shorten the hospital stay, and reduce the mortality rate. During recovery, TCM can improve patients' symptoms, promote organ function recovery, boost the quality of patients' life, and reduce the nucleic-acid repositive conversion rate. A series of mechanism research studies revealed that capability of TCM to treat COVID-19 through antiviral and anti-inflammatory effects, immune regulation, and protection of organ function via a multicomponent, multitarget, and multipathway approach.