The World Health Organization has confirmed the potential emergence of a new variant, dubbed deltamicron or deltacron — a combination of delta and omicron.
Six things to know:
1. Three COVID-19 infections in southern France were identified with a delta 21J/AY.4-omicron 21K/BA.1 recombinant, or deltamicron, according to a preprint published March 8 in MedRxiv. The study, which has yet to be peer-reviewed, found that the hybrid genome has signature mutations of the two lineages. It's similar to cases reported for 15 other patients sampled since January 2022 in Europe. The mutation is misidentified with current PCR variant screening, so researchers designed and implemented a new test to diagnose the variant.
2. The new coronavirus variant has been detected in France, the Netherlands and Denmark, according to WHO officials. It's also been found in the U.S., according to a new report soon to be published by MedRxiv, as viewed by USA Today.
3. The U.S. study findings come from San Mateo, Calif.-headquartered lab Helix, which works with the CDC. The lab sequenced 29,719 coronavirus samples collected nationwide from Nov. 22 to Feb. 13, according to the findings cited by USA Today. Researchers found two infections involving different versions of deltacron, resulting from the combination of delta and omicron genetic material. Twenty other infections had both the delta and omicron variants, with one case having delta, omicron and deltacron. The recombinant variant appears unlikely to spread as easily as delta or omicron, William Lee, PhD, vice president of science at Helix, told USA Today.
4. "We have not seen any change in the epidemiology with this recombinant," WHO COVID-19 technical lead Maria Van Kerkhove, PhD, said of deltacron during a March 9 media briefing. "We haven't seen any change in severity. But there are many studies that are underway."
5. Recent findings from the Pasteur Institute in France also provide evidence of a delta and omicron recombinant. In response to the findings, Dr. Van Kerkhove urged individuals to revisit a Feb. 22 WHO briefing where officials discussed the possibility of coronavirus recombinants.
"This is to be expected, especially w intense circulation of omicron & delta," she tweeted March 8.
6. Researchers have identified other potential recombination mutations, such as multiple cases of alpha infections that also had amino acid substitutions that correspond to the delta-plus, iota and omicron variants, according to a study published March 8 in the Journal of Clinical Investigation. The researchers conducted a "deep sequencing analysis" of COVID-19 among vaccine-breakthrough patients and found "a rich reservoir of mutant types."