Recombination of delta and omicron variants of Covid observed by scientists

Researchers at the Institut Pasteur in France have made public the first strongest evidence of a recombination of the delta and omicron variants of Covid. Such an event is not, at least so far, a cause for concern.

Data on recombination were published in GISAID, an international database where virus genomes, such as those of variants of Sars-CoV-2, are deposited.

According to GISAID itself, the recombinant virus has been circulating since January in several regions of France and there are detections of similar genomes in Denmark and the Netherlands (it is not yet known whether they derive from a single ancestor).

In a Twitter post on Tuesday (8), Maria Van Kerkhove, epidemiologist and technical lead at the WHO (World Health Organization) for Covid-19, said that this type of recombination is expected with the intense circulation of the omicron variants. and delta and that the WHO team is following and discussing the matter.

At the end of February, the topic had already been discussed by experts in a WHO question and answer session. At the time, Kerkhove reassured people about recombination events and explained that this process is basically a joining of “pieces” of one variant with “pieces” of another.

“I don’t want to scare people with the idea of ​​recombination,” Kerkhove said on Feb. 22. “Maybe we’ll start to see recombinations. That could happen, but it could be a reflection of better surveillance.”

On the same occasion, Lorenzo Subissi, a scientist at the WHO, stated that coronaviruses are known for recombination. “We see this a lot in bats,” he said. “The more the virus circulates, the greater the chance of these events happening.”

Subissi stated that recombination should be thought of in the same way as mutations, which happen all the time, and which do not necessarily have an effect on the functioning of the virus.

Anderson Brito, a virologist and researcher at the Todos pela Saúde Institute, says that a recombinant virus will not necessarily have a competitive advantage. “So, so far, it’s not a major concern.”

The virologist points out, however, that the recombinations are relatively rare and difficult to detect. Three recombinant strains have already been described during the pandemic, he said, with the recombination of B.1.634 and B.1.631 (known as the XB strain) being the most widespread, mainly in the United States and Mexico. Currently, however, it is very difficult to find.