Despite the vast amount of research on the new coronavirus known as SARS-CoV-2, little is known about its origin. Indeed, the source of the virus is hotly debated, some theories indicate natural origin, and others claim that the virus was accidentally leaked from the laboratory.
Here’s what we know about the origin of SARS-CoV-2:
The virus was first reported in Wuhan, China.
In late December 2019, health officials issued the first warning about a pneumonia outbreak in Wuhan, China. These cases turn out to be the first reported cases of COVID-19 in the world. By early January 2020, researchers had identified a new coronavirus behind the case. Live science previously reported.. The virus was then officially named SARS-CoV-2.
It is closely related to the bat coronavirus, but the source of the animal is unknown.
The closest known one associated with SARS-CoV-2 is the coronavirus first identified in the horseshoe-shaped bat in Yunnan, China in 2013. FactCheck.org.. Known as RaTG13, the virus shares 96% of its genome with SARS-CoV-2. However, RaTG13 has a specific sequence, and it was not possible to jump directly from bats to humans.
And the viruses are so different that researchers believe that SARS-CoV-2 is not a descendant of it.
Rather, it is suspected that an unknown precursor of SARS-CoV-2 jumped into an intermediate host, which infects people with the virus.
This intermediate host has not yet been identified.Many animals — including Pangolin, Dogs, and even snakes-proposed as possible intermediate hosts, but none have been proven.
According to FactCheck, it is possible that the virus jumped directly from the bat to a person without an intermediate host, but to support this theory it is necessary to find a bat virus that is more closely associated with SARS-CoV-2. There is. .org.
As part of the World Health Organization’s (WHO) investigation into the origin of SARS-CoV-2, researchers tested more than 80,000 samples from wildlife and livestock such as bats, cattle and chickens, but SARS-CoV- Was not detected. According to FactCheck.org, 2 in either sample. Some scientists say it can take years to identify the animal source of SARS-CoV-2.
The Wuhan market sold animals known to carry the coronavirus.
Many of the first cases of COVID-19 were associated with the South China seafood market in Wuhan, and researchers initially suspected that this market was where the virus diverged from animals to humans. However, when researchers tested animal products on the market, none were tested positive for SARS-CoV-2. Live science previously reported.. In addition, researchers later discovered early cases of COVID-19 that were not market-bound, and some that were linked to other markets.The· WHO survey The results released in March concluded that there could be no firm link between the South China Market and the origin of the virus.
However, other studies suggest that the virus may still have occurred on the market. A study published in the journal in June Science report A survey of the Wuhan market for wildlife sales between 2017 and 2019 revealed that there were more than 47,000 animals from 38 species sold on the market during this period. New York Times.. Of these, 33 are known to carry diseases that can also be transmitted to humans. In particular, in this study, mink, palm civet, and raccoon dogs are on the market, and these animals are known to carry the coronavirus.
A specialized research institute in Wuhan has studied coronavirus.
Shortly after the COVID-19 pandemic began, many pointed out that it was also home to a prominent virological laboratory known as the Wuhan Institute of Virology. Here, researchers have studied the coronavirus. Coronaviruses also include viruses that cause severe acute respiratory syndrome. Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS).
This institute is China’s first “Biosafety Level 4” institute, which means it meets the standards for treating the world’s most dangerous pathogens. Live science previously reported.. A group of laboratories led by virologist Shi Zhengli focused on the coronavirus and discovered the possible cause of the first SARS outbreak in 2003. The group also identified the RaTG13 virus. Some wonder if researchers in the lab accidentally infected the coronavirus that the team was studying. However, there is no solid evidence to support this theory. None of the coronavirus sequence published by the lab is closely associated with SARS-CoV-2, although lack of transparency hinders investigation.
WHO states that the natural spillover is the most likely explanation.
The March 2021 WHO report concluded that spillover from wildlife through intermediate hosts was the “very likely pathway” for the first transmission of SARS-CoV-2 to humans. .. Many experts agree. After all, other recently emerging human coronaviruses, including those that cause SARS and MERS, were of animal origin.
“Both lab and natural scenarios are possible, but not equally possible. Priorities, data, and other evidence of nature, as a scientific theory with a high likelihood of the emergence of SARS-CoV-2. I strongly support its emergence, but the lab leak remains a speculative hypothesis. It’s based on speculation. ” Kistian Andersen, a professor of immunology and microbiology at the Scripps Research Institute in La Jolla, California, said. Times..
Labreak theory remains viable.
However, other experts say that Labreak theory may still need to be investigated. In May, more than 12 researchers wrote in Science, claiming that both Labreak theory and Ripple theory were “feasible.” Live science previously reported..
The letter states in the WHO report that “the two theories did not have a balanced consideration” and “there were no clear evidences of natural spillover or laboratory accidents.” ..
Lack of transparency hinders investigation.
Many countries have also criticized the WHO report, conducted in collaboration with Chinese scientists, for lack of transparency and incomplete data. Live science previously reported.. Even WHO Director Tedros Adhanom Ghebreyesus said the research team faced problems accessing Wuhan data, including data on early cases of COVID-19. According to CNN..
President Joe Biden called for a new investigation into the matter by a deadline in late August. Statement from the White House Published in May.
Originally published in Live Science.
Seven facts about the origin of the new coronavirus
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