Researchers at home and abroad found that the


  new crown virus had spread slowly in Asia and Europe before the autumn of 2019.

  ◎Our reporter Lu Chengkuan

  The latest discovery!

The new coronavirus spread independently in Asia and Europe in the early stage.

  Researchers from Sun Yat-sen University, Kunming Institute of Zoology, Chinese Academy of Sciences, National Center for Bioinformatics, University of Chicago and other domestic and foreign units have found that although the new coronavirus strain in Asia first attracted public health attention, before the fall of 2019, The new coronavirus has spread slowly in Asia and Europe respectively.

As a result of the competition between the two new coronaviruses, by April 2020, the Asian strain has been completely replaced by the European strain.

Related research results were recently published in the "National Science Review".

  Regarding the origin of the virus and the spread of the epidemic, it is necessary to distinguish the two different concepts of "the place of origin of the virus" and "the place where the epidemic broke out."

The origin of any organism, whether it is a human, a dog, or an angiosperm, often has a long evolutionary process, during which biological characteristics will be formed step by step.

  The origin of the virus should be the habitat of sparsely populated and animal hosts, where the virus can start an "arms race" with its animal hosts.

Subsequently, the virus evolved and matured and then spread to people who were not immune.

The place where the epidemic broke out is exactly different from the place where the virus originated. The reason is that the people in the place where the epidemic broke out are not immune to the virus, which means that the people have not been exposed to the virus beforehand.

  In short, the origin of the virus must have certain conditions for the virus to gradually spread from animals to humans in a long process.

So far, there is still no clear scientific evidence and definitive conclusions about the origin of the new coronavirus.

  From the perspective of population health, the really important issue is not the origin of the virus, but the spread of the epidemic.

The virus began to spread after it left the place of origin. Although the most noticed area was the first epidemic area at the beginning, which was the first place where the epidemic was officially reported. However, the virus is likely to invade several different places from the origin and cause the epidemic. .

  In the past, the focus of research was on virus analysis by strain.

Because the number of strains is huge, with millions of sequences, it is easy to overlook the initial changes one by one.

This research focuses on the study of mutation sites.

The total number of mutation sites is less than one hundred, so it is easy to grasp the evolution of the virus in the early, middle and late stages.

  Researchers have discovered that the evolution of viruses is a series of "mutant groups" replacement.

From the beginning of 2020 to the end of 2021, there will be at least 5 waves of "mutant groups" in the new crown epidemic.

Each wave is triggered by a strain with a new mutant group.

  The first wave of "D614G mutant group" in early 2020 is very special, and it is also the focus of this research.

The four mutations in this mutation group (hereinafter referred to as the DG group mutation) after the population spread, not only did not disappear, but became the cornerstone of the entire epidemic.

  More importantly, when the epidemic first started in early 2020, the DG group mutation was already the main strain in Europe, and it was discovered in Italy in September 2019.

Before March 2020, mutations in the DG group were not found in China, and they are extremely rare in Asia.

  Therefore, the new coronavirus spread independently in Asia and Europe in the early stage.

Mutations in the DG group appeared in Europe and spread globally.

After that, another 4 waves of new strains spread, including the most recent delta mutant strains, all of which continue to evolve from the DG group mutant strains.

During the evolution of the new coronavirus, the replacement of mutant strains has occurred many times, and new replacements may occur in the future.