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The Wuhan Virus Research Institute, in the whirlwind of public opinion, is located in a not remote location in eastern Wuhan.
The new coronary pneumonia epidemic has spread across the world for almost five months. It remains a mystery how this newly discovered coronavirus crosses species barriers and enters humans from wild animals. Chinese epidemiological experts also appear to be indifferent to how the first patients were infected.
The information gap has brought the discussion on the origin of the virus to an unprecedented ferocious and chaotic state. Since February, conspiracy theories that the new coronavirus may have come from the laboratory of a virus research institute in Wuhan have been on social media. Specifically, there are two types of rumors: some people think this is China’s secret bioengineering investigation, and another group of people think these viruses are natural, but were accidentally leaked due to laboratory accidents.
These statements were later adopted by some politicians. Especially in the United States, the Republican government is stepping up efforts to blame China for the virus. US President Donald Trump and Secretary of State Mike Pompeo are repeating this narrative before the next election.
However, aside from China’s fierce counterattack, this statement has not been recognized by American scientists and the intelligence community, even close American allies are cautious about it. Chinese authorities insist that the origin of the virus has not yet been determined. Chinese Foreign Ministry spokesman Zhao Lijian hinted on social media that the virus was brought to Wuhan by the US military.
So in addition to the “slimy war” between politicians in the United States and China, why does the scientific community disagree with the leaked Wuhan lab and how do they see the possible source of the virus and the difficulty of tracking the fountain? Is it really possible that the virus comes from outside China?
BBC Chinese has an in-depth conversation with seven infectious diseases and virologists from the United States, Australia, France, the Netherlands, and other countries, taking it scientifically and rationally to the starting point of this global epidemic.
Why is it unlikely to leak from the lab?
The Wuhan Virus Research Institute, located in the vortex of public opinion, is located in a not remote area in eastern Wuhan, not far from the great university city of Wuhan and picturesque East Lake. This virus institute with a history of more than 60 years is a research institute of the Chinese Academy of Sciences and the only P4 biological laboratory in China.
P4 is the fourth highest level in the biosecurity standard, which means that the most dangerous viruses are studied here. The pathogens under study often do not have effective vaccines or therapeutic medications, such as Ebola virus, green monkey disease virus (Marburg virus), etc.
In the eyes of the interrogators, this makes their theory seem reasonable. In the early stage of the outbreak, because a sizable portion of the infected people were merchants and customers of the South China seafood market across the river, researchers once thought the market was the initial outbreak of the outbreak. But since the first patients were found to have no history of exposure to the South China seafood market, many people returned their suspicions to the laboratory.
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A bat is a mammal that can fly like a bird, usually leaving during the day and night.
John S Mackenzie is an infectious disease professor with nearly 50 years of research experience at Curtin University in Australia. In 2003, he was the head of the first technical inspection mission in China to investigate the origin of the SARS epidemic. He believes that the probability of leakage of virus from the laboratory is extremely low, because all P4 laboratories in the world must undergo a rigorous review of the same standards to avoid accidental leakage.
“We call this type of laboratory a box within a box,” he told the BBC. These labs often have multiple safety procedures to ensure that it is difficult to fail at the same time.
Angela Rasmussen, a virologist at Columbia University School of Public Health, shares the same opinion. She told the BBC that historically all new viruses, including the H5N1 / H7N7 / H7N9 flu virus, the MERS virus, the Ebola virus and the Zika virus, are naturally occurring and have yet to appear. due to laboratory accidents. A precedent for new viruses.
However, this alone cannot convince those who question, especially when it is discovered that the Wuhan Virus Research Institute has been studying the bat coronavirus and SARS-related viruses, and it is considered that the bat virus it is very similar to this new coronavirus.
Shi Zhengli, 55, is a researcher at the Wuhan Virus Research Institute. In recent years, he has been working on genetic sequence analysis of bat-borne coronaviruses. In January 2019, she was one of the authors and, predictably, published in the international academic journal Viruses, “bats can cause a wave of outbreaks of SARS or MERS coronaviruses in China.” It is more likely to happen. “
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Shi Zhengli, 55, is a researcher at the Wuhan Virus Research Institute and has become the core of many new corona virus conspiracy theories.
In February of this year, she and her colleagues published an article in the authoritative journal “Nature,” noting that the bat strain RaTG13 has a genome homology of 96% with the new coronavirus, making it the “relative” more close to the new coronavirus. RaTG13 was discovered by Shi Zhengli’s team in a cave in Yunnan in 2013, and its samples have been stored in the virus institute’s laboratory. So is this other evidence of “filtered theory”?
Sharon Lewin is director of the Peter Doherty Institute for Infections and Immunity in Australia and told the BBC that although the new coronavirus is similar to RaTG13, it is the channel that enters the human body (i.e. the ACE2 receptor) has unique characteristics, therefore, RaTG13 will not infect human cells.
Furthermore, the scientists also emphasized that in terms of evolution, the genomic difference of 4% is really huge.
“Although RaTG13 is the closest relative to the new coronavirus, it still differs from it by the evolution that takes decades to complete,” said Rasmussen of Columbia University. “Genetic evidence suggests that this virus is derived from a natural bat coronavirus, many of them from wild bats in China.”
Professor Dale Fisher is the president of the Global Outbreak Alert and Response Network of the World Health Organization (WHO) and told the BBC that in a few months, the new coronavirus More than 100 have been produced mutations, and this level of activity further demonstrates that the evolution of this virus can only be completed in nature.
“The coronavirus is obviously more likely to mutate in the throats of millions of bats flying around than in a safe laboratory,” said Fisher.
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Wuhan has been gradually unlocked, but some communities are still closed.
So what is the most likely explanation?
The emergence of new viruses always makes humans panic and accident, but experts say there are all kinds of viruses in different animals in the wild. Occasionally they cross the population and spread to humans or other animals. This is what virologists are concerned about. The phenomenon of “spreading” the virus, which is also the most likely way to spread the new coronavirus.
Angela Rasmussen said that almost any time, as long as humans are exposed to wild animals, human and animal overflows can occur.
“People walk outdoors, enter caves, find animals in the wild or in the market, animals that live in their homes, urine or feces that have been in contact with animals … In many, many cases, people will encounter animals naturally, many times I don’t know, “he said.
Gerald Keusch is a professor of international medicine and health at Boston University. He told the BBC that in the Nipah outbreak in Bangladesh, there were records showing that when humans drink fruit juice contaminated with bat urine or saliva, people can become directly infected, meaning that bats can directly spread the virus.
According to a study published in the “Virologica Sinica” (“Chinese Virology (English version)” by Shi Zhengli’s team from the Wuhan Virus Research Institute in 2018, scientists have surveyed in Yunnan and found that about 2.7% of The population living near bat caves has Coronavirus that produces antibodies.These viruses are not necessarily harmful to the human body, nor do they necessarily become epidemics.
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The wet products market is very common in Asia and other regions. Wild animals are not necessarily sold here, but the humid and messy environment can easily become a virus “amplifier”.
But Professor Kush believes that bats are more likely to gradually spread to other mammals and eventually spread to humans in close contact. Just as the SARS virus can spread from bats to civet cats, or the MERS virus can be introduced to humans through dromedaries.
Sharon Levine also believes that the most likely situation today is multiple transmission between species. He noted that the genetic sequence of the new coronavirus is similar to that of the bat coronavirus, but also to some isolated pangolin viruses in different parts of southern China. This means that the pangolin can also be a link in the middle.
“But we don’t know how and where this happened,” he said.
The South China Agricultural University announced on February 7 that pangolin was discovered to be likely the intermediate host of the new coronavirus. Their published research showed that the team used samples from 25 Malaysian pangolins intercepted by the Guangdong Forest Customs Office of Public Safety and Customs from March to December 2019, and found that the coronavirus genes are similar to the new coronavirus, especially the S. Body protein, “almost the same”.
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The special genome of the bat effectively inhibits replication of the virus itself, but these deadly viruses are easily transmitted to other animals.
Another team made up of the Guangxi Medical University, the University of Hong Kong and other different units took samples of the Malay pangolin intercepted by the Guangxi authorities between August 2017 and January 2018, and found the new coronavirus and coronavirus in these pangolins. . There are similarities
Professor McKenzie said that while it is not yet clear who the intermediate host is, or even how many intermediate hosts, the spread of the virus will almost certainly require an “amplifier”, which may be the South China seafood market, where cases of aggregation occurred before, or is another place.
Professor Kush explained that the initial cases of human infection should be sporadic, but in the mixed market, due to the multitude of people and animals, the virus will rapidly evolve and spread rapidly through the crowd, and will then move to susceptibility with travels. A pandemic emerged from the crowd.
How hard is it to find the source?
Another question that people often pay attention to is: how difficult is it to find the original infected person, that is, “patient zero”? Why has it been 5 months and humans still seem lost?
Professor Kush believes that the first difficulty in finding “patient zero” is because scientists have difficulty determining when the disease will begin. He said that before analyzing clinical samples that occurred in and around Wuhan in early December, November, or even October, it was impossible to judge “Patient No. 0”.
Alexander Gorbalenya, a virus expert from Leids Universitair in the Netherlands, told the BBC that because different people have a different physique, he may already be in the crowd before the virus becomes really “aggressive”. . It has spanned weeks or even months. He believes that due to Wuhan’s huge population, it has become more difficult to trace the original source of infection.
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Studies have shown that the new coronavirus is similar to the pangolin coronavirus.
Angela Rasmussen agreed, saying that the new coronavirus has a wide range of diseases in the human body, from cough and fever to pneumonia. Initially, the patient may be asymptomatic or suffer from an extremely mild illness, but the virus is not discovered until enough people are infected and serious enough to require hospitalization.
Currently, China says traceability work is in progress, but no further progress and details have been announced. The latest official information on the first patients remained on February 26, when the Wuhan municipal government stated that the first patient was Chen, who had not been to the South China seafood market, and became ill on December 8.
However, according to an article published in “The Lancet” medical journal by frontline doctors and Chinese experts in Wuhan, the first patients diagnosed in Wuhan had already developed symptoms on December 1. “South China Morning Post” quoted an internal investigation document from the Chinese government, saying that based on the tracing of previous patients, the first new coronavirus patient may have entered the medical system on November 17.
“(The first patient) is just a novel plot adored by the amateur media,” said Dr. Simon Wain-Hobson, a virologist at the Institut Pasteur in Paris. “This person may be constantly changing, we can only try to find the first batch of infected people.”
Professor Sharon Lewin said that current researchers should work on several lines at the same time. First, wild animals carrying coronaviruses must be extensively sampled, including bats and pangolins outside of China to determine possible intermediate hosts; second, the original virus sequences left over from the Wuhan market must be further analyzed and tested; Third Serum samples routinely collected from blood banks should be tested for new coronavirus antibodies, which will provide important information for the starting point of the outbreak.
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A man in Shanghai walked through a sign to pay tribute to medical personnel in Wuhan.
“It would be a more scientifically significant method if it is clear that the new coronavirus naturally reproduces in other hosts, close relatives and other siblings,” Gorbalonia added.
However, experts said that after the outbreak, Wuhan authorities carried out a large-scale disinfection and cleaning of the South China seafood market on January 1, and closed the market, making it difficult to trace.
When the SARS epidemic erupted in China 18 years ago, Hong Kong scientists rushed to collect animal samples from the Guangdong market before the market closed. They quickly found a virus with 99.7% homology to the SARS virus gene, so they found it quickly. In the case of an intermediate host, this process will undoubtedly take longer for this outbreak.
As the origin of the virus has entered international politics, some people have wondered if it is possible that the new coronavirus comes from outside China.
Last week, when a hospital in the Paris suburbs verified data from hospitalized patients with pneumonia in December last year, they were surprised to find that a patient tested positive for the new coronavirus on December 27, which was more than the official diagnosis on January 24. Wuhan’s couple arrived almost a month earlier.
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Sharon Lewin said that although the new coronavirus may arrive in Europe sooner than previously thought, it is difficult to change the “narrative of Chinese origin” based on the similar viruses found in bats and pangolins that have been found so far.
Simon Wayne-Hobson said there are two definitions of origin: the global pandemic of the new crown originated in China, and the origin of the virus that caused the pandemic may not be. For example, pangolins carrying similar coronaviruses, which were seized by customs officials, came from Malaysia, and HIV has spread from many parts of Africa for many years to large-scale outbreaks in the Great Lakes region of Africa. Oriental.
According to a study published in the medical journal Infection, Genetics and Evolution, a recent genetic analysis of the new coronavirus carried by more than 7,600 patients worldwide showed that the virus has been rapidly since the end of last year. Global spread, which ruled out the assumption that the virus had spread worldwide before it was discovered.
“It is all based on professional international research,” said Professor Kush. “The darkness only increases the conspiracy, and the truth is the light that scatters the conspiracy.”
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