Research: Corona virus may have been transmitted to humans for decades

The SARS-CoV-2 virus may have been quietly spreading among people for years before the outbreak of Covid-19, according to research by some of the world's leading virologists.

SCMP cites results from a US, UK and Australian expert on the evolutionary history of the new corona virus, hypothesizing that the SARS-CoV-2 virus may have been transmitted from animals to humans from long before it was first discovered in Wuhan, Hubei, China.

While there may be other possibilities, scientists say the new corona virus appears to carry a special mutation not found in animal hosts but appears in epidemic outbreaks. Small tissue related to humans .

The international team of experts believes that the new corona virus has been passed between people for decades before the outbreak of Covid-19.(Artwork: AP)

The research was conducted by scientist Kristian Andersen from Scripps Research Institute (California, USA), Andrew Rambaut from Edinburgh University (Scotland), Ian Lipkin from Columbia University (New York, USA), Edward Holmes from Dai. studied at Sydney (Australia) and Rober Garry from Tulane University (New Orleans, USA). The research content was published in the scientific journal Nature Medicine on March 17.

Francis Collins, director of the National Institutes of Health (NIH), who was not involved in the study, said the findings could suggest a scenario that a new corona virus was transmitted between animals and people long before it caused Covid-19 in humans .

'Due to gradual evolution over many years or perhaps decades, the new corona virus has gradually gained the ability to spread from person to person and cause serious, potentially lethal pathogens,' said Collins. comments in an article posted on the NIH website on March 26.

In December, doctors in Wuhan began to detect a rapid increase in the number of patients with strange pneumonia. However, tests for colds and other strains of the virus were negative. An unknown strain has been isolated and scientists from the Wuhan Institute of Virology have traced its origin to a bat found in a cave near the China-Myanmar border.

The two viruses are 96% identical in genome but the bat virus does not infect humans because it lacks protein spikes to bind to receptors in human cells.

A team of doctors in Wuhan late last year discovered a strange disease originating from a previously unrecognized virus strain (Artwork: SCMP).

A team from Guangzhou and Hong Kong later found corona viruses with a spike in protein in the Malaya pangolin, raising the hypothesis that there was a genetic recombination between the bat virus and the pangolin virus. .

However, according to Andersen et al., The SARS-CoV-2 strain had mutations in the genome that were not found in any corona virus in bats or pangolins.

According to other independent studies from experts from China, France and the US, the mutation could create a special structure in the viral protein spikes to bind to furin, an enzyme in the human body. This may have enabled fusion between the virus envelope and the human cell membrane.

Some human-to-human viruses, such as HIV and Ebola, also have a similar mechanism involving furin, making them viral strains.

According to the study, it is completely possible that the mutation of the corona virus took place naturally when it was on the animal host. The virus that causes the Sars or Mers outbreak is also thought to be a 'descendant' of the virus found on civet and camel, with 99% genome matching.

However, there is no similar evidence for the new strain of corona virus because the difference between human and animal viruses is quite large. So Ardersen's team came up with a different theory.

The study says that it is possible that the ancestors of SARS-CoV-2 were transmitted from animals to humans, after which they adapted and changed and caused human-to-human transmission. These adaptations later turned the disease into small outbreaks, sufficient for the surveillance system to detect its existence.

According to Collins, the study almost completely rejected the hypothesis that the new corona virus originated in the laboratory.

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