The highly transmissible omicron subvariant BA.5 continues to gain dominance in the U.S., now accounting for nearly 82 percent of confirmed COVID-19 cases in the U.S., according to the CDC's latest variant proportion estimates.
BA.5 accounted for 81.9 percent of cases in the week ending July 23, while BA.4 made up 12.9 percent, the estimates show. BA.2, the nation's dominant strain this spring, now accounts for just 0.3 percent of all cases.
"We are in BA.5 mode," Anthony Fauci, MD, director of the National Institute of Allergy and Infectious Diseases, told The Hill July 25.
Federal health officials are planning to authorize an omicron-specific vaccine booster designed to target BA.5 in the coming months, which Dr. Fauci called the "best guess" for dealing with COVID-19 this fall.