“Deltacron” is probably a lab mistake, not a new variant

Coronavirus infections linked to the covid-19 omicron variant are continuing to surge. In the US, hospitalizations are approaching record highs, and officials in China reported the first known omicron cases there on Jan. 9, prompting mass testing and quarantines in the city of Tianjin. If that weren’t enough, a scientist in Cyprus said on Jan. 7 that his team had identified a new covid-19 variant in 25 patients, that appeared to be a combination of the delta and omicron variants. He dubbed it “deltacron.”

It is possible for coronavirus variants to “recombine” their genomes and form new strains. But in this case, “deltacron” appears to be red herring—or as molecular biologist Eric Topol of the Scripps Research Translational Institute put it on Twitter, a “scariant.”

The deltacron variant data in Cyprus looks like testing contamination

Tom Peacock, a virologist at Imperial College London, concurred. Omicron has likely not circulated for long enough, in a large enough population, to produce a true recombinant, he said. And in any case, genetic details of “deltacron” published on the GISAID database don’t resemble a recombinant. Instead, they “look to be quite clearly contamination” of the lab in which the sequencing took place.

“Most likely [all the samples] were all sequenced on the same sequencing run in the same lab on the same day which had a contamination issue – this is what’s generally been found to have happened in the past,” he said.

Other new variants are still likely to emerge sooner or later. But a deltacron variant, Topol said, is “one less thing to worry about.”