Coronavirus: how many lessons have we learned in the past ten years?

Before the outbreak of SARS, no one knew that the coronavirus was so infectious The existence of coronavirus has been known for a long time As a virus that can infect the respiratory tract and digestive tract of animals and human beings, it has not been paid enough attention to for a long time This arrogance is also understandable - in healthy people with normal immune capacity, the coronavirus can only cause very mild symptoms A coronavirus that may cause SARS (picture source: [public domain]) However, in the first decade of the 21st century, SARS broke out According to the data in July 2003, the SARS virus has caused 8096 cases of infection and 774 deaths in 27 countries Ten years later, 1728 confirmed cases and 624 lives were brought to 27 countries in the Middle East respiratory syndrome caused by mers virus Novel coronavirus has come back again in the third ten years of this century According to a review paper on Nature Reviews Microbiology published in 2018, coronaviruses can be divided into four categories according to their genomes and structures, among which α and β will only infect mammals, while γ and δ will mainly infect birds SARS and mers viruses, which we are familiar with, are all β - coronaviruses Behind the transmission of these viruses to humans, we can not do without the participation of other animals Take SARS as an example In civet cats, scientists found the early virus strain of SARS Many people who have close contact with civet cats have become infected with SARS Further studies have shown that civet cats are only "intermediate hosts" and that the source of the virus may be bats Mers virus is more complex Although scientists also believe that the viruses originally came from bats, there are signs that camels have become "repositories" of such viruses This can explain why, in the Middle East, where people have more contact with camels, there have been cases of human infection with mers virus; on the contrary, for SARS, since there are few opportunities for humans to have direct contact with bats, no new cases of SARS have been observed after the disappearance of the infected intermediate host There are animal sources of coronavirus (picture source: reference [1]) From the novel coronavirus infection situation, many early cases were related to the Southern China seafood wholesale market, also in line with our current understanding of the origin of the coronavirus ▲ according to past experience, hospital environment is the main place for "people to people" (photo source: reference [2]) From the past situation of coronavirus infection, the hospital environment is indeed the main place where "human to human" occurs In 2016, another review published by Nature Reviews Microbiology analyzed the cases of SARS and mers, and pointed out that "43.5% - 100% of mers individual outbreaks are related to hospitals, and very similar phenomena have been observed in some SARS population" Among them, the transmission of mers virus is the most common way, accounting for 62% - 79% of cases For SARS virus, the infection between patients and medical staff is also frequent (33% - 42%) The pathology of SARS and mers are very similar Both of them can rely on the glycoprotein on the surface of the virus to bind to the receptor on the surface of the cell, and release RNA in the cytoplasm, which can guide the synthesis of new virus particles The difference is that SARS virus recognizes ACE2 receptor, while mers virus recognizes DPP4 receptor In addition, these viruses have a variety of strategies for "immune escape" to prevent the innate immune system from responding to them For SARS and mers, we still lack effective antiviral therapy, so we can only provide some auxiliary treatment Also in a review published in 2016, the authors noted that most of these patients were treated with ribavirin and various interferons, sometimes with broad-spectrum antibiotics and oxygen In the treatment of SARS, there are also ribavirin combined with corticosteroids In addition, lopinavir and ritonavir, which are used to treat HIV infection, are also used to treat some patients with coronavirus infection Finally, the authors point out the serum and antibody of patients in self-healing period, which may bring some help However, this review also indicates that although these methods have achieved efficacy in non-human primates, they have not been tested in human clinical trials, so it is difficult to evaluate their specific efficacy rigorously In addition, the follow-up analysis can not fully confirm the effectiveness of these combination therapies due to the lack of cases, the lack of control group and other reasons At this point, our past experience in treating SARS and mers may be relatively limited Nearly 20 years have passed since the outbreak of SARS In the past 20 years, we have not made enough progress in the fight against the new pathogen, coronavirus And we haven't learned enough from the past in terms of still being exposed to wildlife and lack of adequate treatment Looking forward to the future, we hope to learn from the previous cars, on the one hand, reduce the possibility of virus infection to human beings from the source, on the other hand, accelerate the development of new therapies and even vaccines The coronavirus has brought us a health crisis for three decades in a row In the next decade, we expect to hear no more of its name reference material: [1] Cui, J., Li, F & Shi, Z Origin and evolution of pathogenic coronaviruses Nat Rev Microbiol 17, 181–192 (2019) doi:10.1038/s41579-018-0118-9 [2] de Wit, E., van Doremalen, N., Falzarano, D et al SARS and MERS: recent insights into emerging coronaviruses Nat Rev Microbiol 14, 523–534 (2016) doi:10.1038/nrmicro.2016.81 [3] Infection prevention and control during health care when novel coronavirus (nCoV) infection is suspected, Retrieved January 20, 2020, from https:// Note: the article is deleted A kind of