麻豆传媒

There's yet another new variant on the block -- the so-called "Eris" variant -- but it's still an Omicron subvariant and researchers say there's no reason to expect it to cause a surge of COVID-19.

For the 2-week period ending August 5, the projects that Eris, or EG.5, made up 17.3% of cases in the U.S., making it the most common variant for that time period.

XBB.1.16 is a close second, projected to make up 15.6% of cases for that time period.

The prevalence of EG.5 more than doubled from a month ago, when it came in at 7.5% of samples for the 2 weeks ending July 8, according to CDC data.

EG.5 and its relatives EG.5.1 and EG.5.1.1 are also on the rise in the U.K., with an estimated prevalence of 14.55% as of July 20, according to the .

It did, however, have the greatest weekly growth advantage rate of any variant, at 45.65%, according to that report.

The World Health Organization listed EG.5 as a "" -- lower than its "variant of interest" category -- in mid-July, and traces the earliest documented samples to February 17 (WHO currently lists no "variants of concern").

WHO technical lead for COVID-19 Maria Van Kerkhove, PhD, said during a late July press briefing that EG.5 is an Omicron lineage -- specifically, it is a sublineage of XBB.1.9.2. Vaccines for this fall target XBB strains of the virus.

T. Ryan Gregory, PhD, an evolutionary biologist in Canada, reportedly gave the variant its "Eris" nickname via (formerly known as Twitter). He linked to a , a dwarf planet in the solar system.

Shishi Luo, PhD, associate director of bioinformatics and infectious disease at Helix, which tracks SARS-CoV-2 variants in the U.S., said discussion on GitHub indicates that EG.5 has a mutation in its spike gene that may moderately increase immune escape, but at the same time it may have diminished binding affinity.

"We don't really know exactly what advantage it has, but it is playing out in increased cases attributed to this variant," Luo told 麻豆传媒.

She noted, however, that the recent uptick in COVID cases overall doesn't appear to be due to this variant, but it remains to be seen "whether that bears out in the next month."

"Even though summer is not usually associated with respiratory disease, and even though we feel like we know how to deal with COVID and the pandemic is behind us, I think we should still be prepared to see an increase in cases," Luo said. "It's a good reminder that we still don't have the nationwide infrastructure required to do this kind of surveillance."

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