Both novel coronaviruses and SARS viruses are coronaviruses. There are 50 known species of coronaviruses, which can be divided into four major groups. Previously, there were four coronaviruses associated with the common cold. In 2003, SARS emerged, a new coronavirus, to which most people are not resistant, showing symptoms such as fever and pneumonia; in 2012, Middle East Respiratory Syndrome, called MERS, also a coronavirus, emerged. The new coronavirus that emerged this time is genetically close to the SARS virus and has a high similarity rate, but is not exactly the same. In terms of clinical manifestations, they have in common that both can cause fever and pneumonia. They both pass through the angiotensin-converting enzyme II receptor after entering the body, and both can manifest as fever, cough, shortness of breath and other respiratory symptoms, but differences can exist because the viruses are not completely identical. For example, the new coronavirus pneumonia is more contagious. The number of infections worldwide has exceeded 100,000, more than 10 times the number of confirmed SARS, indicating that it is more contagious. However, the rate of death and the severity of the impact on human health is lower than that of SARS. content source: Dr. You Lai