While multiple countries have confirmed cases of a coronavirus recombinant consisting of parts of both omicron and delta, some scientists have said the common nickname "deltacron" may be misleading.
The World Health Organization has confirmed the existence of the recombinant, but hasn't deemed it a variant of interest or concern, which would mean it would receive a Greek letter. Meanwhile, unofficial names for the variant continue to circulate.
Two U.S. cases have been identified by San Mateo, Calif.-headquartered lab Helix. Researchers sequenced 29,719 coronavirus samples collected nationwide from Nov. 22 to Feb. 13 and found two infections involving different versions of deltacron, resulting from the combination of delta and omicron genetic material. Study findings have yet to be peer reviewed.
The deltacron cases in the U.S. involved separate omicron sublineages paired with delta, which is where the name "deltacron" could be problematic, said William Lee, PhD, vice president of science at Helix, according to U.S. News & World Report.
"It is a little bit misleading in the sense that there's actually many different delta-omicrons," Dr. Lee said. "Even within our publication, there's at least two different ones."
One preprint study in France referred to the variant as "deltamicron." Other scientists are referring to the hybrid as the AY.4/BA.1 recombinant, according to The New York Times.
"Viruses constantly change through mutation and sometimes these mutations result in a new variant of the virus," according to the CDC. "CDC and other public health organizations monitor all variants of the virus that causes COVID-19 in the U.S. and globally. Scientists monitor all variants but may classify certain ones as variants being monitored, variants of interest, variants of concern and variants of high consequence."
Currently, there's no evidence that the recombinant is more transmissible or severe than delta or omicron. Multiple studies regarding the recombinant are underway, according to WHO officials.