(Reuters) – The fast-spreading BA.4 and BA.5 sub-variants of Omicron are estimated to make up a combined 52% of the coronavirus cases in the United States as of June 25, the U.S. Centers for Disease Control and Prevention (CDC) said on Tuesday.
The two sublineages accounted for more than a third of U.S. cases for the week of June 18. They were added to the World Health Organization’s monitoring list in March and designated as variants of concern by the European Centre for Disease Prevention and Control.
Several vaccine makers including Pfizer Inc, Moderna Inc and Novavax Inc are testing versions of their COVID vaccines updated to combat the Omicron variant.
Pfizer and Moderna have said their new vaccines also appear to work against the subvariants, even though that protection is not as strong as against BA.1.
Outside experts to the U.S. Food & Drug Administration are meeting on Tuesday to discuss whether to change the design of COVID-19 vaccines in order to combat future variants.
BA.4 made up 15.7% of the variants in the United States for the week of June 25, while BA.5 made up 36.6% of the variants, according to CDC estimates.
The seven-day moving average of U.S. COVID-19 cases stood at 101,378 as of June 25, up 2.9% from a week earlier.
(Reporting by Mrinalika Roy in Bengaluru; Editing by Anil D’Silva)
