International war "epidemic" operation
Recently, researchers from the University of Glasgow in the UK published the latest research results on the origin of the COVID-19 virus in the journal Science. The new findings confirmed the earlier conclusions, pointing out that there may be an "intermediate animal host" for the introduction of the COVID-19 virus into humans. The paper believes that the emergence of the COVID-19 virus has characteristics consistent with natural spillover, and the possibility of human manipulation by the Wuhan Institute of Virology is extremely small.
Civet cats may serve as a channel for the SARS virus to spread from horseshoe bats to humans
In 2005, researchers discovered that horseshoe bats in China were carrying the SARS virus. They speculated that "Sarbecovirus (B-coronavirus branch B, the subgenus of coronavirus to which the COVID-19 virus belongs) spread among horseshoe bats sowed the evolutionary ancestor of SARS virus into an intermediate animal host."
By studying badgers, civet cats, and raccoon dogs, the researchers finally identified civet cats as the most likely animal host, serving as a channel for the SARS virus to spread from the horseshoe bat host to humans, but the civet cat is not a long-term host species. They speculated that it was possible that the civet cats in captivity initially contracted the SARS virus through direct contact with bats foraging on the market, or it was possible that they were infected with the virus before they were captured.
Genetic evidence debunks the so-called "laboratory leak theory"
The Wuhan Institute of Virology reported that the RaTG13 virus had spread in Yunnan horseshoe bats (chrysanthemum bats). Therefore, some people regard RaTG13 as the source of the COVID-19 virus. At the same time, at the end of 2019, the COVID-19 virus appeared in Wuhan, China. Some people insisted that the Wuhan Institute of Virology was the source of the pandemic and believed that it cultivated the RaTG13 virus.
In this regard, the research paper clearly stated that Wuhan is more than 1,500 kilometers away from Yunnan Province, and the virus cannot be transmitted from Yunnan to Wuhan. The author explained that the geographical range of horseshoe bats is very wide, from eastern China to western China to Southeast Asia and Japan, and even farther. The susceptibility of this species to Sarbecovirus is in the middle or lowest level. It is wrong to focus solely on Yunnan horseshoe bats.
The paper also pointed out that the viruses collected from Yunnan "are very different from the predecessor of the COVID-19 virus", and the evolutionary distance between the two is at least 40 years. RaTG13 cannot be the predecessor of the COVID-19 virus. These key genetic evidences negate the "laboratory leak" theory related to the Wuhan virus.
In addition, the paper cited a review article on COVID-19 virus traceability by 21 authoritative scientists from the United States, Britain and other countries, and believed that "the emergence of COVID-19 virus has characteristics consistent with natural spillover", and the possibility of the virus being manipulated by the laboratory. Extremely small. "Even if bat dung is collected as fertilizer, it is much more than the number of times that researchers go to bat caves to conduct research from time to time." The researchers wrote in the paper.
The epidemic may be caused by contact between humans and live animals carrying the virus
So, how did the COVID-19 virus enter the human body?
Studies have shown that intermediate host living animals that are susceptible to SARS-related coronaviruses play a central role as the main source of COVID-19 virus progenitor cells that humans come into contact with, just like the origin of SARS. In other words, the spread of the virus caused by contact between humans and living animals carrying the SARS-related coronavirus is the most likely cause of the COVID-19 pandemic. But the exact animal source of the COVID-19 virus is still unclear.
The paper stated that humans are now the main host species of the COVID-19 virus. The current danger is that the COVID-19 virus may spread from humans to other animal species, which is the so-called "reverse zoonosis" phenomenon. Studies have shown that one-third of white-tailed deer in the northeastern United States have antibodies to the COVID-19 virus, indicating that they have been infected with the COVID-19 virus. How they are infected with the COVID-19 virus has become a big mystery.
The paper stated that the mixed infection of Sarbecovirus to different host species means that SARS-related coronaviruses are likely to overflow from wild animals in the future, and current vaccines may not be able to prevent new mutations. In order to better understand this spillover risk, it is urgent to increase the sampling intensity of Sarbecovirus.
The paper emphasizes that humans must work together across national borders to expand the surveillance of coronaviruses at the human and animal levels to minimize the threat of existing mutations and the evolving evasion of vaccine antibody mutations, and prevent future virus spills from happening. .
0 Comments