(Reuters) - The U.S. Centers for Disease Control and Prevention (CDC) on Friday estimated that by Oct. 8 nearly 14% of the circulating coronavirus variants in the United States were of the BA.4.6 subvariant of Omicron.
In the week ending Oct. 8, the BA.4.6 subvariant is expected to make up 13.6% of total COVID cases in the U.S., higher than the 12.7% prevalence last week.
The subvariant has been slowly increasing in prevalence across the U.S., even as the BA.5 subvariant of Omicron remains the dominant strain with 79.2% of the cases.
The BA.4 and BA.5 subvariants had in recent months been driving a surge of new infections globally. The U.S. recently started administration of vaccine boosters specifically retooled to target the two subvariants.
The BA.4.6 subvariant has been found to be better at evading COVID-19 antibody therapies, with the U.S. Food and Drug Administration in early October warning healthcare providers that AstraZeneca (NASDAQ:AZN)'s Evusheld had the risk of being ineffective against some variants it cannot neutralize.
According to the FDA's fact sheet, the BA.4.6 subvariant was likely to have more than 1,000-fold reduction in susceptibility to the antibody therapy, based on laboratory tests.