The rumor of the discovery of a new strain resulting from the fusion of two main variants currently in circulation is going around the Internet. But it would simply be due to an error in an analytical laboratory. For now.
What if the delta and omicron variants combine? This is the nightmare scenario sketched out by Leondios Kostrikis, professor at the University of Cyprus. His remarks made during an interview with Cypriot television Sigma TV Friday were picked up by the Bloomberg agency on Friday. We read that“There are currently omicron and delta co-infections and we have found a strain that is a combination of the two” in the country, according to Leondios Kostrikis. The researcher named his discovery “deltacron”, due to the identification of omicron-like genetic signatures in delta genomes.
The name has flourished and is one of the most used words on Twitter this Sunday. The posts are a mix of schoolboy merger jokes and worries about a new transmissible, dangerous, and re-infecting super-variant landing. A very premature fear.
Indeed, even Leondios Kostrikis, in his interview, said he was betting on a victory for omicron in this match of viral strains. Above all, his discovery could only be the result of improper handling in his laboratory. This is what several scientists think on Twitter. They analyzed the genetic sequences of 25 Cypriot cases of “deltacron” deposited on the international database Gisaid.
Possible path for rapid evolution of omicron
Gisaid makes it possible to create the genealogical tree of the virus (phylogenetics). And, surprisingly, these “deltacron” sequences do not end up in the same place. “The Cypriot ‘Deltacron’ sequences that several mainstream media are talking about seem to be quite clearly a contamination – they do not cluster on a phylogenetic tree”, affirms this Saturday Tom Peacock, virologist at the prestigious Imperial College in London. Samples from patients contaminated by omicron, and others by delta, could have been found in error in the same analysis, thus suggesting a fusion between the two variants.
While awaiting confirmation that “deltacron” is indeed a false alarm, this case highlights a possible path of rapid evolution for Sars-Cov-2, called “recombination”. The principle is simple: the same patient must be infected with two different strains of the virus. A rare event but possible when two strains circulate a lot like at the moment in Europe with delta and omicron.
The two viruses must then infect the same cell in the patient’s body at the same time. There, their genetic information will mix and it will emerge a new strain probably very different from the previous two. According to Tom Peacock, always on twitter, we expect to see this kind of recombinants appear after a few months of co-circulation of the variants. It would therefore still be a bit early for the moment. But this alert reminds us that, even if we hope the opposite, the appearance of another variant which will still relaunch the epidemic after omicron is still possible.