For future studies, we recommend prospective cohort studies, RCTs or registry studies to evaluate the effect of CPMs in prevention of COVID-19. Some clinical trial protocols to treat COVID-19 using the top 10 CPMs are ongoing (see  Table 4 ). At present, since COVID-19 has not yet been controlled, a series of prospective population studies with rigorous design and large sample should commence with protocol registration, and implementation in a timely manner, to produce reliable evidence for CM prevention of COVID-19 or similar emerging respiratory infectious diseases in the future.