Opening of borders is uncertain: new strain of coronavirus BA.2.75 worries Chinese and international experts

Today, articles about the new coronavirus strain BA.2.75 appeared in Chinese and foreign media, which caused concern among Chinese and international experts.


Reportedly, a new variant of the strain Omicron under the number "BA.2.75" attracted the attention of scientists in Israel and other countries. This variant is derived from the BA.2 variant of the Omicron strain and is referred to as the "second generation variant" which has many "unusual" mutations or can break through the immunity created by existing vaccines and infections of the strain, the infection rate is relatively high, cases have occurred in India, Japan, USA and other countries. Relevant experts fear that this option could replace existing options such as BA.2 and BA.4, leading to a new peak in the epidemic worldwide.


As of July 2, researchers from different countries have found the gene sequences of 85 BA.2.75 variants in international novel coronavirus genome databases such as GISAID. This variant first appeared in the gene sequence from India in early June and then quickly appeared in the UK, USA, Japan, Canada, Australia, New Zealand, Germany and 7 other countries. Since the number of new coronavirus genomes shared by countries is only the “tip of the iceberg” of the global number of new coronavirus cases, the actual number of people infected with the BA.2.75 variant far exceeds 85.


Dr. Shai Fleishen, an expert at the Israel Ministry of Health's Central Virus Laboratory, said on social media that the emergence of BA.2.75 is "worrisome" as it is a "second generation variant" that evolved from BA. Variant 2. Compared to BA.2, there are 16 new mutations, of which 8 are located in the region of the gene for the spike protein.


Bloom Labs in the US stated on its social media platform that compared to BA.2, this variant has two key mutations, G446S and R493Q, of which G446S will alter antigenic characteristics, helping the virus break through the immune system and the barrier created by existing vaccines. , R493Q improves the ability of the virus to enter human cells, so BA.2.75 is very worthy of further monitoring.


British virology expert Tom Peacock said that BA.2.75 has a large number of spike protein mutations, is a "second generation variant", has a rapid spread and wide geographic distribution, which requires close attention.


BA.2.75 could be the first “second-generation variant of the coronavirus.”

As explained by Shay Fryson, Tom Peacock et al., the so-called "second generation variant" refers to the evolution from the "first generation variant" but with more mutations and greater differences from the first generation variant. option. For the Omicron strain, variants BA.1, BA.2, BA.3, BA.4, BA.5, and others are referred to as a “first generation variant,” while BA.2.75 could be the first “second generation coronavirus variant.”


Shay Fleason said that prior to BA.2.75, researchers had found many "second-generation variants" of the new coronavirus - "these samples can be found every day" - but none of the previously discovered variants were large. sample size, while BA.2.75 has spread across several countries with dozens of sample sizes and appears to have been successful. BA.2.75 is only the first "success" and represents the "next step" in the evolution of the Ormicron strain (i.e. creating more "second generation variants") and more complex genetic changes may occur in the future.


Tom Peacock said that "second generation variants" evolved from already existing successful variants that already have "unpleasant" antigenic transmission characteristics, which may mean they are more dangerous.


Studies have shown that the BA.2 variant of the Omicron strain is more infectious than the earlier BA.1 variant. At the end of last year, after the emergence of the Omicron strain, the BA.1 variant for the first time caused an unprecedented peak of the epidemic around the world, in March-April of this year, BA.2 gradually “displaced” BA.1.


Many experts believe that BA.2.75 is likely to have a competitive advantage over other coronavirus strains.

According to a study by Australian data processing expert McHaney, BA.2.75 is spreading extremely fast. From June 15 to June 30, the proportion of this variant in genome samples uploaded to India rose rapidly from less than 5% to 18%, indicating that its crowds out other options and seems to spread faster than options BA.2 and BA.5.


Raj Rajnaryanan, assistant professor of biology at New York Institute of Technology, also believes that BA.2.75 could replace BA.5, BA.4, and other proliferating variants of BA.2, and there is too little current data. be reliable, whereby its growth advantage may become apparent within a few weeks.


Tom Wenslers, professor of biology at the University of Leuven in Belgium, also said that he is quite confident that the BA.2.75 height advantage over BA.5 is real.


Ulrich Erling, a researcher at the Institute for Molecular Biotechnology at the Austrian Academy of Sciences, said that before we get past wave BA.5, we can be ready for the next wave BA.2.75