New COVID Variant EG.5 Now Dominant in U.S., CDC Says

By   |  August 8, 2023

By Cara Murez HealthDay Reporter  |  Copyright © 2022 HealthDay. All rights reserved.

TUESDAY, Aug. 8, 2023 (HealthDay News) – A variant nicknamed Eris now accounts for the largest proportion of new COVID infections across America.

About 17.3% of U.S. COVID cases are believed to have been caused by the variant, formally known as EG.5, in early August, according to the U.S. Centers for Disease Control and Prevention. That number is 7.5% higher than it was in early July.

Other dominant variants include XBB.1.16, with 15.6% of cases, and XBB.2.23, with 11.2% of cases, CDC data show. Another 10.3% of COVID cases are from XBB.1.5, while 8.6% of cases were caused by an XBB-related variant known as FL.1.5.1.

Experts say EG.5 might be beating out other variants because it appears to have a "slightly beneficial mutation," CBS News reported.

Eris is one of several closely-related Omicron subvariants that have been competing for dominance in recent months. All of these variants are descendants of the XBB strain, which is the target of this fall's COVID shots.

"While the emergency of COVID has been lifted and we're no longer in a crisis phase, the threat of COVID is not gone. So, keeping up with surveillance and sequencing remains absolutely critical," Dr. Maria Van Kerkhove, the World Health Organization's technical lead for COVID, said in a statement last month.

Because the CDC has slowed its tracking of COVID variants, it was not able to project EG.5's emergence until now since only California, Georgia and New York have had enough sequences to update national data, CDC officials said.

While tens of thousands of sequences were uploaded to virus databases earlier in the pandemic, now that is less than 2,000, CBS News reported.

"Because Nowcast is modeled data, we need a certain number of sequences to accurately predict proportions in the present," CDC spokesperson Kathleen Conley told CBS News. "For some regions, we have limited numbers of sequences available, and therefore are not displaying Nowcast estimates in those regions, though those regions are still being used in the aggregated national Nowcast."

More information

The World Health Organization has more on COVID-19.