Delta-Omicron hybrid variant 'Deltacron' identified

Hybrid versions of the coronavirus that combine genes from the Delta and Omicron variants, dubbed "Deltacron," have been identified in at least 17 patients in the U.S. and Europe, researchers said.

As there have been few confirmed cases, it is too soon to say if Deltacron will be highly transmissible or cause severe disease, said Philippe Colson from IHU Mediterranee Infection in Marseille, France, lead author of a reportposted on March 3 on medRxiv ahead of peer review.

His team described three patients in France infected with a version of SARS-CoV-2 that combines the spike protein from an Omicron variant with the "body" of a Delta variant.

Another two unrelated Deltacron infections have been identified in the U.S., according to an unpublished report by genetics research company Helix that has been submitted to medRxiv and seen by Reuters.

Screenshot of report named "Culture and identification of a 'Deltamicron' SARS-CoV-2 in a three cases cluster in southern France" posted on medRxiv, March 3, 2022.

On virus research bulletin boards, other teams have reported an additional 12 Deltacron infections in Europe since January, all with an Omicron spike and a Delta body.

Genetic recombinations of human coronaviruses have been known to happen when two variants infect the same host cell.

"During the SARS-CoV-2 pandemic, two or more variants have co-circulated during same periods of time and in same geographical areas. This created opportunities for recombination between these two variants," said Colson, adding that his team has designed a polymerase chain reaction (PCR) test that "can quickly test positive samples for the presence of this virus."