SARS-CoV-2 jumped from bats to humans with little genetic alteration: study

A new study found that SARS-CoV-2, the virus that causes COVID-19, jumped from bats to humans without much genetic alteration.

According to a collaborative study between researchers in the United Kingdom, the United States and Belgium, the study found few “significant” genetic changes in the sequenced viral genome during the first 11 months after December 2019. I am. Coronavirus Pandemic.Survey results published in open access journals PLOS Biology..

Glasgow University researcher Oscar McLean said, “This does not mean that no changes have occurred, but hundreds of evolutionarily important mutations have accumulated, as is the case with all viruses. He said he would “surf” along with all the communication events.

Certain changes affect SARS-CoV-2, such as the spiked alternative D614G, which has been shown to increase transmissibility. Eure Calerto OK. However, scientists have pointed out that the “neutral” evolutionary process dominates.

“This stagnation may be due to the highly sensitive nature of the human population to this new pathogen, with limited pressure from herd immunity and lack of containment, leading to exponential growth. Connect and almost every virus will be the winner, “explained McLean.

The lead authors of this study, David L Robertson (MRC-University of Glasgow Center for Virus Research, Scotland) and Sergei Pond (Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia), use their expertise to analyze data. Is done. From HIV and other viruses for the study of SARS-CoV-2.

Pond said the virus prevalence is “amazing” and that viruses that jump from one host to another usually take longer to adapt.

“What is very surprising is how infectious SARS-CoV-2 was from the beginning. Viruses that jump to new host species are usually as capable as SARS-CoV-2 when spreading. It takes time to get the adaptation, and in most cases it does not go through that stage, resulting in dead-end spillover effects and local outbreaks, “pound commented.

Scientists investigated the mutational process of SARS-CoV-2 and related salvecoviruses, or a group of viruses in which SARS-CoV-2 belongs to the bats and pangolins, and found that “evidence of a fairly significant change. I found. But they said all this happened before the virus reached the human host.

Therefore, this study suggested that the “generalist” nature of the coronavirus and its tendency to jump from host to host gave SARS-CoV-2 the ability to infect humans and other mammals. It is believed to have evolved in bats.

Towards the end of 2020, SARS-CoV-2 came into more frequent contact with existing host immunity as the number of infected individuals increased. Scientists say this has increased the number of variants that can prevent some of the host’s responses from popping up.

“The reason for the SARS-CoV-2’gear shift’in terms of increased evolutionary rate at the end of 2020, associated with more highly mutated strains, is due to changes in the immunological profile of the population. “Robertson added.

Researchers said SARS-CoV-2 is still an acute virus, meaning that the immune system can eliminate it in most cases. However, it is important to note that the virus is increasingly different from the January 2020 variant used in all current vaccines. Vaccines work against most of the mutants that circulate, but this changes over time, increasing the difference in the number of vaccinated and unvaccinated people.

“The first competition was to develop a vaccine. The current competition is to get people around the world to get the vaccine as soon as possible,” Robertson said.

Last week, the United States surpassed the 100 million COVID-19 vaccines administered. CDC.. More than 29.3 million cases of coronavirus have been identified and more than 534,000 have died in the country. Data from Johns Hopkins University..

In the last century, 40 species of bats moved to southern China, Laos and Myanmar. Genetic analysis suggests that a virus known as SARS-CoV-2 first appeared in this area. Photo: AFP / Ye Aung THU