The CDC's Nowcast data tracker, which displays COVID-19 estimates and projections for two-week periods, reflected that the KP.3.1.1 variant accounted for 57.2% of positive infections, followed by XEC at 10.7% in the two weeks starting on Sept. 29 and ending on Oct. 12.

The CDC is "monitoring the XEC variant," Rosa Norman, a CDC spokesperson told USA TODAY. This variant "is the proposed name of a recombinant, or hybrid, of the closely related Omicron lineages KS.1.1 and KP.3.3."

The XEC variant of the coronavirus has begun spreading globally. The clearly dominant symptom is loss of appetite, but previously known symptoms also appear. In the first half of October, over 12,000 cases were reported in Poland.

"CDC is monitoring the XEC variant," Rosa Norman, a CDC spokesperson told USA TODAY. "XEC is the proposed name of a recombinant, or hybrid, of the closely related Omicron lineages