Deltacron COVID Variant, Mix of Delta and Omicron, Found in at Least Four Countries

A COVID-19 variant that appears to be a mixture of both Delta and Omicron has been found in several countries, including the U.S.

At the moment, it's not clear what sort of characteristics this variant might have and studies are ongoing.

On Tuesday, French researchers reported three cases in southern France of people being infected with a COVID-19 variant that was a mixture of the Delta AY.4 and Omicron BA.1 viruses, which the researchers dubbed "Deltamicron."

Similar mixtures have been described before and have been popularly known as "Deltacron."

The variant mixture, known as a recombinant, is described as being made of "the near full-length spike gene of an Omicron BA.1 variant in a Delta AY.4 lineage backbone" in the French report, which was published in the pre-print journal medRxiv.

It also noted that 15 similar hybrid variant cases had been reported to the GISAID virus database as of February 27 this year.

It should be noted that the report has not yet been peer-reviewed so its findings should be interpreted with caution.

The recombinant then came up in a World Health Organization (WHO) press briefing the following day. In it, Maria Van Kerkhove, the WHO's COVID-19 technical lead, said the variant had been detected in France, the Netherlands, and Denmark, but added that there were "very low levels of this detection."

"We have not seen any change in the epidemiology with this recombinant, we haven't seen any change in severity, but there are many studies that are underway," Van Kerkhove said. "Unfortunately we do expect to see recombinants because this is what viruses do; they change over time."

In addition, another two unrelated Deltacron infections have been reported in the U.S., according to an unpublished report by genetics research company Helix, Reuters reported on Wednesday.

Thais is not the first time Deltacron viruses have been reported. In January this year, genomes with mutations from both Delta and Omicron were reported in Cyprus, but several scientists questioned the results due to signs of contamination.

Krista Queen, director of viral genomics and surveillance at Louisiana State University Health Shreveport, told Newsweek that the January reports differ from the newer data which "does not show signs of being from lab contamination," she said.

Regarding what this new Deltacron variant might be like, Queen said it is too soon to make any guesses and it would be "better to wait for experimentation and real-world observations gathered."

Jeremy Kamil, associate professor of microbiology and immunology also at Louisiana State University Health Shreveport, told Newsweek: "The epidemiological characteristics are not worrying. We are talking about small numbers of cases.

"I'm not even sure you should call it Deltacron because the name was originally coined from an error, and these ones—in fact there are multiple real ones now—isn't an error."

COVID lab
A stock photo shows laboratory workers possibly researching COVID samples. "Deltacron" sequences, a combination of Omicron and Delta variants, have been reported in several countries. Godji10/Getty