(Reuters) -The U.S. Centers for Disease Control and Prevention (CDC) on Friday estimated that Omicron subvariants BQ.1 and BQ.1.1 accounted for about 35% of coronavirus cases in the country in the week ending Nov.5 compared with 23.2% in the previous week.
The subvariants made up nearly 9% of total cases in the week of Oct. 15 and their proportion has been rising steadily among circulating cases since then.
The two variants are descendants of Omicron's BA.5 subvariant and have been spreading rapidly in Europe. The European Centre for Disease Prevention and Control has said they were likely to become the dominant variants shortly and drive up cases in the next few weeks and months.
There is no evidence yet that BQ.1 is linked with increased severity compared to the circulating Omicron variants BA.4 and BA.5, the European agency said, but warned it may evade some immune protection, citing laboratory studies in Asia.
New variants are monitored closely by regulators and vaccine manufacturers in case they start to evade protection offered by current shots.
U.S. Food and Drug Administration said on Friday that Eli Lilly (NYSE:LLY)'s experimental COVID drug, bebtelovimab, was not expected to neutralize these Omicron subvariants.
BQ.1.1 made up nearly 19% of circulating variants and BQ.1 was estimated to make up 16.5% of circulating cases in the week of Nov. 5, the U.S. CDC said on Friday.
The figure for the previous week was updated from 27.1% earlier.
The BA.5 subvariant, which drove up cases earlier this year, is estimated to make up about 39% of cases, compared with nearly 51% in the week ended Oct. 29.
Coronavirus cases saw a small uptick for the week ended Nov. 2, data from CDC showed. This comes after a gradual decline in reported cases from July highs.