[New crown virus] Pneumonia epidemic: Where did the new crown virus come from? Several statements in the scientific community

[New crown virus] Pneumonia epidemic: Where did the new crown virus come from? Several statements in the scientific community

 

    The novel coronavirus epidemic has been called by the United Nations "the biggest crisis after World War II." After the outbreak in China at the end of last year, it spread to many countries around the world in just a few months. In this crisis, international politics have disputes over the source of the virus, and social media has spawned various "conspiracy theories."

1. Is it manual manufacturing?

    Wuhan, China, was the hardest-hit area where the virus was first discovered and triggered a widespread epidemic. The South China Seafood Market in the city has been confirmed as one of the important sources since December last year.

    At first, the outside world did not know much about the virus. Many people thought that the virus might be related to the Wuhan Institute of Virology near the South China Seafood Market. Without providing any specific scientific evidence, the question was a "biochemical weapon." The Chinese government, research All official agencies immediately refuted the unconfirmed fake news.

    In March 2020, China and the United States quarreled over the naming of the virus. US President Trump and Secretary of State Pompeo repeatedly referred to the new coronavirus as "Chinese virus" and "Wuhan virus", which caused dissatisfaction in China. Chinese Foreign Ministry spokesperson Zhao Lijian questioned on Twitter that the virus "may be the US military that brought the epidemic to Wuhan."

    The question of the Chinese official once again brought up the discussion about whether the virus was artificially created. Senior American officials and even European and American media quickly accused Chinese officials of taking the lead in spreading unconfirmed fake news.

    Many "experts" circulated on the Internet claiming that the virus "may" or "do not rule out" artificial manufacture, but so far, no research report published in international academic journals believes that the virus may be artificial manufacture. On the contrary, many authoritative studies have confirmed that the virus evolved naturally, not artificially.

    In February of this year, the authoritative medical journal "The Lancet" published a joint statement by 27 scientists from eight countries, stating that scientists from various countries analyzed the genome of the new coronavirus and reached an "overwhelming" conclusion that the new coronavirus and other emerging Like the pathogen, it originated from wild animals, and strongly condemned the conspiracy theory of the unnatural origin of the new coronavirus.

    The international journal Nature published a research report co-authored by experts from the United States, Australia, and the United Kingdom in March, referring to the study of the characteristics and structure of the virus, including its recombinant receptor binding domain (RBD) and polyzygosity site (Polybasic cleavage site), determined that the virus "cannot be artificially made."

    RBD is the thorn protein that the virus hooks to the host cell, that is, the crown-shaped part of the coronavirus. Researchers believe that the ability of proteins to connect with human cells so effectively is difficult for existing science to do. This is one of the non-human evidence.

    The "cut site" of the virus is the tool for the virus to open the host cell. If it is artificially made, the molecular structure of the virus will be based on other existing viruses that can cause disease. However, researchers have found that the backbone of the virus is very similar to the existing virus. Not the same, the virus has no trace of artificial synthesis.

    Kristian Andersen, an assistant professor in the Department of Immunology and Microbiology at the Scripps Research Institute in the United States, who wrote the study, said that combining these two points, it is certain that the virus originated from natural evolution, but it will take more time to study In order to know the path of its natural evolution.

    This report has been described by many European and American scientists as the end of the "virtual conspiracy theory."

2. What kind of animal is the virus related to?

* Hong Kong infectious disease expert Yuan Guoyong withdraws the article "The Origin of the Pandemic in Wuhan" arouses controversy.
 

* Start a battle to trace the source of the virus from wild animals.

    The emergence of the new coronavirus has attracted different scientists around the world to participate in research and come up with various opinions and theories. However, sometimes, because the research results are published to the media too early, some research has been overturned.

    For example, in the early days, some scientists compared the virus with a few genes of several animals and concluded that snakes might be the host of the virus; some scientists also believe that the new coronavirus spike protein has several inserts similar to HIV-1. This shows the connection between AIDS and the new coronavirus. These two studies were quickly overturned by other scientists who provided evidence.

    As time progresses, experts have obtained a more complete genetic sequence of the virus and can make a more comprehensive comparison study. The current mainstream of the scientific community believes that the virus is related to bats and pangolins.

    The team of Shi Zhengli, director of the Wuhan Institute of Virology Research Center for Emerging Infectious Diseases, was the first to discover that the new crown virus is related to bats. Their research published in the authoritative journal Nature in early February pointed out that the new crown virus is related to the genes of the Yunnan bat virus strain (RaTG13) The sequencing has 96% similarity. It is believed that bats are the natural host of the new coronavirus, but the spike S protein receptors of the two viruses are not the same. At that time, the evolution of the virus was not fully understood.

    This study is widely cited, and international experts are inclined to gradually evolve viruses from animals to humans.

    South China Agricultural University in China announced on February 7 that it has discovered that pangolins are likely to be the intermediate host of the new coronavirus. The research they published showed that the team used the Guangdong Forest Public Security Bureau and Customs to extract samples from 25 Malayan pangolins intercepted from March to December 2019, and found that the coronavirus is genetically similar to the new coronavirus, especially its S The protein receptors are "almost the same," inferring that pangolin may be an intermediate host, and its coronavirus may have evolved with the Yunnan bat virus strain (RaTG13).

    Another team composed of different units such as Guangxi Medical University and the University of Hong Kong took samples from Malayan pangolins intercepted by Guangxi authorities from August 2017 to January 2018 and discovered the new coronavirus and the coronavirus on these pangolins. There are similar similarities. The study also pointed out that pangolin may be a potential host of the new coronavirus. The article believes that pangolins should not be sold in the wet market to avoid the spread of the virus from animals to humans. The study was also published in the journal Nature on March 26.

    The BBC Chinese understands that the Chinese research team does not only conduct research on pangolins, but also searches for samples from various animals that may appear in seafood markets or underground wildlife markets, but this type of pangolin is the most breakthrough in research.

3. Did the virus come from Wuhan, China?

    The source of the virus was first suspected to be the South China Seafood Market where multiple confirmed cases occurred first. On January 22, the director of the China Centers for Disease Control and Prevention once stated at a press conference that the source of the virus was illegally sold wild animals in a seafood market in Wuhan. .

    However, according to the research conducted by Huang Chaolin, vice president of Wuhan Jinyintan Hospital and others on the first 41 confirmed patients, the patients who developed symptoms as early as December 1 were not related to the South China Seafood Market and other confirmed patients, and the source of reflection may not necessarily come from Animals in the market. The research was published in The Lancet on January 24.

    However, scientific research believes that the virus is similar to the coronavirus of Yunnan bats and pangolins smuggled into China. These animals did not come from Wuhan, and the process of virus mutation may not necessarily occur in Wuhan. However, some experts believe that this shows that the virus may have originated in China, and it is most likely to mutate in China first.

    Yuan Guoyong, an infectious disease expert at the University of Hong Kong, wrote in Ming Pao on March 10 that the new coronavirus is similar to the Yunnan bat coronavirus strain, and the S protein receptor of the new coronavirus is similar to the pangolin coronavirus strain as high as 90%. He believes that The virus originated in China and was related to the Chinese "overeating of wild animals". The author later withdrew the article, but the reason was not related to his scientific views, but because he referred to Taiwan as "Republic of China" and the new crown virus as "Wuhan virus."

    Michael Conway, an assistant professor in the Department of Microbiology at Central Michigan University in the United States, told the BBC Chinese that there are related viruses in many species in China. Epidemiological studies have also pointed the first round of outbreaks to Wuhan, showing that the new coronavirus is "obviously The land comes from China". But he emphasized that this kind of virus mutation may occur in various places, "individual countries cannot be blamed, this is a human problem that needs to be resolved together."

    Lin Zanyu, an assistant professor at the School of Public Health of the University of Hong Kong, participated in the study of the new coronavirus and the smuggling of pangolins in Guangxi. He told BBC Chinese that their research alone could not infer whether the Malayan pangolins were infected with the virus in China or Southeast Asia. But he pointed out that illegal smuggling of wild animals inherently risks bringing in foreign pathogens and exposing wild pathogens to humans. He believes that to better understand the source of the virus, more research in China and other countries is needed.

    Zhong Nanshan, an academician of the Chinese Academy of Engineering, said at the end of February that although the new crown pneumonia epidemic first appeared in China, there is no evidence that the virus originated in China. His statement was widely quoted by the Chinese media and the public.

    Based on multiple authoritative scientific documents, there is currently no scientific research or clinical data showing that the outbreak in Wuhan, China, originated from a foreign country. However, Chinese media have repeatedly reported speculations without scientific citations, targeting Italy and the United States respectively.

    For example, Giuseppe Remuzzi, director of the Institute of Pharmacology of Mario Negri, Italy, mentioned in an interview that some local doctors noticed that the elderly had strange symptoms of pneumonia around November and December. His statement was quoted by the Chinese media and pointed out that the epidemic may not have come from China, because the first person in China who discovered the symptoms of the disease is believed to have started to develop the disease on December 1.

    Ramsey later said in an interview with Western media that the Chinese media had distorted his statement. What he wanted to emphasize at the time was that the virus may have spread before anyone discovered it. He believes that based on genetic research, the virus undoubtedly came from China, and believes that the Italian epidemic was brought by a German who had been in contact with Chinese citizens from China to Italy.

    He clarified that at the time he said that Italy had pneumonia before January was based on rumors from a small number of people and doctors, and there was no scientific basis to show that these people had the disease because of the new coronavirus.

    Another infectious disease expert from the University of Milan, Adriano Decarli, also noticed that many people had contracted pneumonia and influenza in Milan at the end of last year. After reviewing hospital records and clinical details, he may be able to open the coffin. To learn more about whether the virus was introduced to Italy earlier, but many experts doubted Decali’s research, believing that if the virus was introduced to Italy earlier, the disease would have broken out earlier.

    U.S. President Trump and Secretary of State Pompeo referred to the novel coronavirus as "Chinese virus" and "Wuhan virus", which caused dissatisfaction in China. At that time, a war of words broke out between the two countries. Chinese Foreign Ministry spokesman Zhao Lijian said without providing definitive evidence that it was possible that "the US military brought the epidemic to China." His statement was criticized by European and American media as officials taking the lead in spreading fake news.

    Chinese officials have not retracted Zhao Lijian’s remarks, but apart from him, no Chinese official or spokesperson for the Ministry of Foreign Affairs mentioned the statement that “the virus comes from the United States” again, and unified that “the virus does not necessarily originate from Wuhan, China, but should "Scientists define" in response.

    Chinese state media "Global Times" reported on March 25, citing an American "reporter" George Webb (George Webb) that the virus may have come from a U.S. military cyclist who went to Wuhan to participate in the World Military Games, but the official Media reports have shown that there is no strong evidence for this claim. George Weber is not actually a "journalist." He is regarded by the US media as a YouTube celebrity on the far-right conspiracy theory.

    There are opinions on the Internet that the virus may exist when the flu breaks out in other countries. However, Zhang Wenhong, the leader of the Shanghai New Coronary Pneumonia Clinical Treatment Expert Team and an infection doctor at Fudan University Huashan Hospital, said in an interview with China Daily that the new crown and influenza There is no confusion, because the new crown has a very characteristic performance on a computer tomography (CT), which is easy to distinguish.

    Zhang Wenhong pointed out that if the Chinese virus is introduced into China from abroad, it should be affected at the same time in several cities, rather than having a time sequence. This visit was later withdrawn by China Daily.