Emerging virus strain prompts research calls

Chinese researchers have sounded the alarm about the possible recombination of SARS-CoV-2－the novel coronavirus that causes COVID-19－with other viruses following the emergence of a hybrid of the Delta and Omicron variants, according to an article released on Monday by the Chinese Center for Disease Control and Prevention.

While mutations are changes in a small segment of a virus' genetic sequence, recombination creates larger shifts in the genetic makeup.

The first solid evidence for a recombinant strain combining the two key virus mutations was detected by researchers in France earlier this month, and it was informally dubbed Deltacron.

"No recombination events involving large genomic fragments (like Deltacron) have been found in SARS-CoV-2 before," the article said. It was released on China CDC Weekly, an academic platform established by the center.

So far, experts from the World Health Organization have said circulation of the new strain is low and no changes have been observed in the severity of infections.

However, it is highly likely that recombination events involving more genetic material will occur in the future, according to the article's authors, Wang Liang, a researcher from the Chinese Academy of Sciences, and Gao Fu, a professor at the University of the Chinese Academy of Sciences and director of the China CDC.

With the widespread transmission of SARS-CoV-2 worldwide, the increasing number of species found to be susceptible to infection, and the variety of animal hosts, recombination might also occur across different species.

As it remains uncertain which viral species SARS-CoV-2 may recombine with and which genes may be transferred, the article said future novel recombinant viruses will likely continue to pose risks to humans.

It suggested stepping up research into the Deltacron strain and adjusting control strategies accordingly.

"It is more important to be alert to the generation of other types of recombinant viruses produced by SARS-CoV-2 and other viruses," it said.

"Therefore, it is particularly important to implement large-scale virome study in both domesticated and wild animals."