A potential new COVID-19 variant, a combination of the delta and omicron variants – you can call it "deltacron" – has been identified.
The World Health Organization said Wednesday that the new COVID-19 combination has been detected in France, the Netherlands and Denmark. It's also been found in the U.S., according to a new report soon to be published on research site MedRxiv, and viewed by USA TODAY.
The San Mateo, California-headquartered lab Helix, which works with the Centers for Disease Control and Prevention to track COVID-19, sequenced 29,719 positive COVID-19 samples collected Nov. 22 to Feb. 13 from across the U.S., according to the research team, which included the University of Washington Medical Center and testing company Thermo Fisher Scientific.
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.
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Should we worry about deltacron?
Experts say it's too soon to worry about deltacron. Compared with earlier variants, such as delta and omicron, this new variation – researchers have not adopted the "deltacron" name officially – appears unlikely to spread as easily, said William Lee, the chief science officer at Helix.
"The fact that there is not that much of it, that even the two cases we saw were different, suggests that it's probably not going to elevate to a variant of concern level" and warrant its own Greek letter name, Lee told USA TODAY.
So far, in the places where deltacron has been detected, "there are very low levels of this detection," said Dr. Maria Van Kerkhove, an American infectious disease epidemiologist and the WHO's COVID-19 technical lead, during a Wednesday press conference.
For now, WHO has not seen "any change in the epidemiology," Van Kerkhove said. And regarding deltacron, "we haven't seen any change in severity. But there are many studies that are underway."
William Hanage, an epidemiologist at the Harvard T.H. Chan School of Public Health, concurs.
"It's only a variant if it produces a large number of cases," he said. "So no, if it's not causing lots of cases, people don’t need to be concerned."
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How do we get COVID-19 variants?
Viruses such as the SARS-CoV-2 strain that causes COVID-19 can change and mutate. For instance, the mutations that caused the delta variant resulted in a variant that made people contagious sooner. The omicron variant itself was more contagious and was found to reinfect some who had previously had COVID-19.
"Unfortunately, we do expect to see recombinants because this is what viruses do, they change over time," Van Kerkhove said. "We're seeing a very intense level of circulation. We are seeing this virus infect animals, with the possibility of infecting humans again. So again, the pandemic is far from over."
Why is deltacron important?
Usually, mutations happen steadily until one becomes strong enough to become a new variant. In this case, there were many different mutations occurring, perhaps as a function of the continued existence of delta amid the omicron wave.
"For a few weeks, co-infection cases probably happened more often than we know of, because they can be difficult to detect," Lee said.
While people may not need to worry about this latest variant, researchers can learn from deltacron's development.
"It's an interesting phenomenon, and it helps us understand more about how the virus evolves and how the pandemic continues to endure," Lee said.
The continuing variants "validate the need for ongoing national surveillance to identify potential variants of concern as part of an early warning system that monitors for new viral trends including COVID-19, flu and other viruses, Lee said.
Testing and constant study of the virus is "critical," Van Kerkhove said.
"It's really critical that we continue with sequencing, that we have good geographic representation of sequencing around the world, and that the systems that have been put in place for surveillance for testing for sequencing, right now be reinforced, that they're not taken apart, because we have to move on to the next challenge," she said.
Follow Mike Snider on Twitter: @mikesnider.
This article originally appeared on USA TODAY: A new COVID variant called Deltacron? Here's what we know