This time the new coronavirus comes in force, people can’t help but think of 2003 SARS (Severe Acute Respiratory Syndrome, a kind of acute respiratory infectious disease caused by SARS coronavirus), so what is the relationship between the new coronavirus and SARS coronavirus? This time, the new coronavirus is coming in force, reminding people of SARS (Severe Acute Respiratory Syndrome, an acute respiratory infectious disease caused by the SARS coronavirus) in 2003, so what is the relationship between the new coronavirus and the SARS coronavirus? First of all, according to the current research, 2019-CoV and SARS-CoV are not subordinate to each other, and there is no such thing as the new coronavirus belonging to the SARS coronavirus; both belong to the same coronavirus. Coronaviruses are a group of pathogens that mainly cause respiratory and intestinal diseases. Under the electron microscope, they appear to have many regularly arranged protrusions on their surfaces, which resemble an emperor’s crown, and are therefore named “coronaviruses”. Our 2019-CoV and SARS-CoV are both variants of coronaviruses, and are at most distant cousins. Secondly, 2019-CoV and SARS-CoV share a gene sequence with a similarity of 79.5% and enter host cells in a very similar way, both entering host cells through the surface of the Spike protein connected to the ACE2 receptor, but they still have a lot of differences, for example, the RBD region of the Splike protein of SARS-CoV has five important residues, while 2019-CoV has just one of them. It is because of these differences that the infectiousness of the two is not the same, and the recent literature shows that 2019-CoV binds more strongly to the human ACE2 receptor, coupled with the fact that transportation is more developed than it was in 2003 and that Wuhan is more densely populated, the number of people infected with 2019-CoV is much higher than that of SARS-CoV in 2003, but the lethality of 2019-CoV is much lower than that of SARS-CoV. CoV is much lower than that of SARS-CoV.(The following table shows the comparison between 2019-CoV and previous infectious poisons, CaseFatalityRate disease mortality rate, R0 basic contagion coefficient: refers to the average number of individuals to whom a person infected with a certain contagious disease will transmit the disease to other individuals in the absence of external intervention and at the same time, all people do not have immunity.) In addition, the two sources of infection transmission pathways are relatively similar. The source of the SARS outbreak in China in 2003 was the Chinese chrysanthemum-headed bat, while the intermediate host was the fruit civet. The natural host of the new coronavirus may also be bats, but the specifics have not yet been determined, and the intermediate host may be pangolin, or there may be more than one intermediate host In general, both are transmitted to humans through wildlife. The routes of transmission are also predominantly airborne, followed by contact, and fecal-oral transmission is controversial. Although the number of people infected by the new coronavirus has exceeded that of the SARS coronavirus, and it is more “cunning” than the SARS coronavirus, the case fatality rate is much lower than that of SARS, and with more experience and higher medical standards, we will be able to defeat the new coronavirus just as we did with SARS!