This article has been reviewed according to Science X's editorial process and policies . Editors have highlighted the following attributes while ensuring the content's credibility:

A new COVID variant with very few known cases but many mutations has been swiftly moved into the World Health Organization's "variant under monitoring" classification.

Four known cases of the variant, dubbed BA.2.86, have been so far identified worldwide, including one case in Michigan.

The U.S. Centers for Disease Control and Prevention said Thursday that it is tracking the new variant.

"Today we are more prepared than ever to detect and respond to changes in the COVID-19 virus," CDC spokesperson Kathleen Conley said in a statement to CBS News. "Scientists are working now to understand more about the newly identified lineage in these four cases and we will share more information as it becomes available."

More data is needed to understand whether or not the variant will be dangerous with its many mutations, WHO said. BA.2.86 includes dozens of genetic changes, CBS News reported. That's similar to the differences observed when the original omicron variant emerged in 2021.

It's possible the variant has been spreading undetected for some time, because there are reports of it in countries on three continents. In addition to the United States, cases have now been spotted in Denmark and Israel, CBS News reported.

The University of Michigan reported the first U.S. case as part of "baseline surveillance" at the university's clinical microbiology lab.

Some of the mutations are in parts of the virus that could help it evade immunity provided by prior vaccination or infection.

"Deep mutational scanning indicates BA.2.86 variant will have equal or greater escape than XBB.1.5 from antibodies elicited by pre-omicron and first-generation omicron variants," Jesse Bloom, an evolutionary biologist at the Fred Hutch Cancer Center in Seattle, said in a slide deck published Thursday, CBS News reported.

BA.2.86 still remains rare. The body also has other defenses that may also help people fight off even this highly mutated variant.

"[T]here are also broader mechanisms of immunity elicited by vaccination and infection that provide some protection against severe disease even for very heavily mutated variants," Bloom noted in an email to CBS News.

Other questions remain, including whether BA.2.86 can outcompete existing, fast-spreading strains descended from the XBB omicron variant that now predominate. If it fails to do so it may not pose any threat, experts believe.

One such XBB descendent, the EG.5 variant, is steadily climbing in dominance and now makes up 1 in every 5 COVID-19 cases in the United States, the CDC said. Right now, the agency said BA.2.86 will remain grouped with its forbearer omicron BA.2 until it reaches at least 1% of known cases.

BA.2.86 is emerging just as vaccine makers are preparing rollouts of a new generation of COVID-19 vaccines, due for launch in September. Those shots are targeted to the XBB strains of the virus, of which EG.5 is closely related.

Vaccine maker Moderna announced Thursday that its shot provides "a significant boost in neutralizing antibodies" for EG.5, CBS News reported.

That efficacy could be undone if BA.2.86 successfully spreads, however. Bloom told CBS News that he believes the new variant has so many mutations it could be a "fairly poor match" for any XBB-targeted vaccine.

More information: The U.S. Centers for Disease Control and Prevention has more on how the agency tracks variants.

Copyright © 2023 HealthDay. All rights reserved.