AmericaBiologist Scott Nguyen, from the Medical Laboratory in Washington, stumbled across a mixed variant of Omicron’s head and Delta’s body.
Scott Nguyen and many colleagues call themselves “mutant hunters”. They are tasked with tracking emerging strains around the city, searching millions of nCoV gene sequences in a huge international database called GISAID. The goal is to find dangerous strains that could change the course of a pandemic, or simply give scientists more knowledge about how viruses evolve.
For example, in November, a mutant hunter found a “very strange set of mutations” from mutations in South Africa. “It ended up being Omicron,” Nguyen said.
Then, one February morning, Nguyen discovered not one, but “a class” of entirely new mutants. This variant mixes parts of Delta and Omicron. Those parts don’t come together at random. The virus seems to have the optimal combination, selecting the best traits from each variant to infect and avoid immunity.
Specifically, Mr. Nguyen found a strain containing mainly Delta components, but carrying Omicron’s spike protein. This is the part that helps the virus attach to human cells and begin to spread.
“So, it has the best part of Omicron which is the spike protein, but the body is still Delta. This is the best way to describe the virus,” Nguyen said.
According to him, in case the patient is infected with two strains of Omicron and Delta at the same time, it is very likely that a “monster strain” will be born. It has “the shell of Omicron and the body of Delta”.
Up to now, this variant is very rare, temporarily called by scientists as Deltacron. It has been found in France, Denmark, Belgium, the Netherlands and Germany, with a few found in the US, UK and Brazil.
The World Health Organization (WHO) and national authorities are closely monitoring the mutation. They demonstrated that the virus had selected the most effective parts and combined them into a “super virus”. This process, called recombination, can produce the deadliest strains of flu.
“Regularly recombinant viruses are the way to create pandemics of influenza. So we need to be very careful, monitor the recombination process very, very closely,” said Dr. Mike Ryan of the WHO.
Omicron’s spike protein helps the virus evade the human immune system, especially antibodies. Thus, the Deltacron mutant is essentially Delta “wearing the cloak of Omicrcon’s invisibility”.
“It’s the mutant with the best features in the world. It’s surprising that the virus actually does this, and it does it very well,” Nguyen said.
Shishi Luo, a biochemistry expert at Helix, agrees with Scott Nguyen’s team’s explanation. Essentially, a hybrid strain is created when a person is infected with both Delta and Omicron at the same time.
Luo and colleagues analyzed samples from 30,000 Americans infected with nCoV from November 2021 to February. They found 20 people co-infected with Omicron and Delta.
“Omicron spreads strongly around Christmas and New Year, when people see each other a lot. Imagine, you go to a party with someone infected with Delta, then go to another place and come into contact with someone infected with Omicron,” Luo said. explain.
According to her, if two strains infect the same cells, the virus can begin to recombine. In essence, during the replication process, the mutant steals a piece of the gene from the other mutant. Thus, Deltacron was born because Delta copied part of Omicron’s genetic code.
The collection of genetic code instead of single genes makes the virus more flexible, rapidly evolving into new versions that can evade immunity.
“This shows how great the potential for nCoV to change itself,” Luo said.
In fact, the phenomenon of recombination has occurred since the early days of Covid-19 infection. Last month, scientists at the University of Glasgow published a conjectural study about the origin of nCoV. Their analysis showed that an animal at the Wuhan seafood market may have been co-infected with two coronaviruses at the same time. These two viruses combine, creating nCoV like the way Omicron and Delta are doing to create Deltacron.
“In the early days of the pandemic, we thought nCoV didn’t mutate too much. But this virus surprised us in many ways. So we think the recombinant strains (hybrid strains) provide interesting clues about how the virus evolved,” said Scott Nguyen.
Thuc Linh (According to NPR)