Delta Croon, a new variant of the two-poison combination is really coming

As of March 16, 2022, the number of people infected with the new crown virus worldwide has exceeded 457 million, and Delta and Omilon are two super virus variants that have successively dominated at different stages of the global epidemic. There are concerns that when these two major viral variants infect the same individual, it is possible to recombine into a new viral variant in their bodies. This phenomenon is very common on RNA viruses such as influenza viruses.

At a press conference on March 9, 2022, the World Health Organization confirmed that delta and omexon's new recombinant variant, the Deltacron variant, has been detected in several European countries, with the delta variant's genome as the backbone, and the gene for the spike protein responsible for invading host cells is mainly derived from the Omilcroon variant. According to the New York Times, similar new variants of the virus have emerged in the United States. More details have been revealed in two recent preprints that have not yet been peer-reviewed.

Many European countries and the United States have seen new variants of the Delta + Omexjong reorganization. (Infographic/Figure)

The earliest claim of the combination of delta and Olmikeron was in late December 2021. At that time, some domestic self-media quoted Indian media reports that the Delmicron strain had appeared. However, soon, India Today clarified this statement, in fact, the so-called Delmicron strain was not found at that time, but it was mentioned that the simultaneous epidemic of Delta and Omikejong strains may push the epidemic to a new climax.

In early January 2022, Leondios Kostrikis, a virologist at the University of Cyprus, announced that his team had discovered a number of new variants of the new coronavirus with both Delta and Omikeron mutations and named them: Deltacron. However, it was soon pointed out that from the viral genome sequence published in the International Virus Database (GISAID), the so-called new variant of Delta Kerong is more likely to be contaminated with the sequencing sample, that is, the sample is mixed with the genomes of the delta and Omilon variants. Although Professor Costrickys denied that the genome sequences he provided were not caused by sample contamination, he deleted the uploaded genome sequences three days after he submitted them to GISAIDs.

The latest research suggests that the Deltakron strain does exist.

On March 8, 2022, researchers at the Institut Pasteur in France published a paper on the website of the preprint medRxiv that confirmed for the first time the existence of a variant of the new coronavirus that contains the characteristics of delta and Omilkeron mutations. When the researchers sequenced virus samples from COVID-19 infected people in southern France from December 27, 2021 to February 14, 2022, they found that the genome of this recombinant variant was based on the Delta 21J/AY.4 genome and the gene sequence expressing the spike protein was dominated by Omilon 21K/BA.1. The researchers called it Deltamicron, formally known as the AY.4/BA.1 recombinant. The three cases of DeltaMicron infected people reported in the paper were all detected in February, and these cases are currently predominantly mild, with two of them receiving 2-3 doses of vaccination. Phylogenetic analysis of the virus showed that this recombinant variant could appear as early as December 2021. Through structural analysis of recombinant spikes, the researchers hypothesized that this recombinant pattern could optimize the binding of the virus to the host cell membrane.

Four days later, helix Laboratory, an American genetic sequencing company, also announced on the paper preprint platform medRxiv that the Delta and Omiqueron variants in the United States were jointly infected and recombined. The researchers sequenced genomes from more than 29,000 COVID-19-positive samples collected in the United States between November 22, 2021 and February 13, 2022, and found two different versions of the Delta Kerong variant. The genomic sequence of this variant is slightly different from the variant found in Europe. According to USA Today, they also identified 20 cases of infection with both Delta and Omikejong, as well as one patient infected with Delta, Omikejong and Delta Kerong.

As things stand, the Delta Crox variant isn't particularly worrying. On the one hand, there are not many cases of the Delta and Occhiron variant infections compared to the surge in infections of the Delta and Omikejong variants, and of course the number of Delta kerong variant infections may be greater than scientists currently know. According to data published by the International Virus Sequence Database, as of 15 March, more than 40 cases of delta kerong AY.4/BA.1 variants have been reported in five European countries, of which 36 new variants have been found in France, 8 in Denmark, and 1 in Germany, Belgium and the Netherlands. Only 15 cases of infection with Deltakjong in the past month have also been detected in the above five countries. In the United States, only 2 patients infected with the Deltacroon variant alone and one patient with the three variants were detected in the nearly 30,000 cases, indicating a very low rate of detection of the Deltacroton variant.

On the other hand, EXPERTS AND OTHER RELEVANT EXPERTS BELIEVE THAT THE DELTAKRON VARIANT DOES NOT POSE A THREAT AND THAT EXISTING VACCINATIONS ARE ALSO EFFECTIVE IN PREVENTING THE VARIANT. "We haven't seen any changes in the epidemiology (of this recombinant variant) or a change in severity, but there are many studies underway." Maria Van Kerkhove, WHO's technical head of COVID-19, said at a news conference on March 9. Soumya Swaminathan, the World Health Organization's chief scientist, wrote on social media Twitter, "We already know that recombinant events can occur in humans or animals, accompanied by multiple circulating variants of the new coronavirus. It is necessary to wait for experiments to determine the characteristics of this virus. As we respond to the epidemic, sequencing, analysis, and rapid data sharing are especially important. Dr. William Hanage, an epidemiologist at the Harvard TH Chan School of Public Health, believes that "if it doesn't cause a lot of cases, people don't need to worry." Because of the small number of cases, the World Health Organization also does not classify it as a "worrying variant."

Southern Weekend Contributing Writer Tombo