A COVID subvariant descended from the original omicron variant remains the most-prevalent strain of the virus in circulation, but there is a new version of COVID-19 that is now the second-most common in the United States.
According to the latest estimates released by the Centers for Disease Control and Prevention on Tuesday, the BA.4.6 subvariant of COVID is now responsible for an estimated 6.3% of cases in the United States, surpassing the BA.4 variant that it descended from.
The BA.4 variant, which began to emerge at around the same time as the BA.5 strain, now makes up 4.3% of U.S. cases, officials estimate.
The BA.5 subvariant has been the dominant strain of COVID in the United States since early July, and although its share of cases has continued to increase, its growth has certainly started to slow in recent weeks.
In all, the subvariant makes up an estimated 88.9% of cases in the U.S., up from the 88% mark that it achieved last week.
According to public health officials, the BA.5 subvariant has shown an increased ability to maneuver around immunity gleaned from previous COVID infections and from the COVID-19 vaccine. It is also significantly more contagious than previous omicron variants.
The COVID vaccine is effective at preventing serious illness and hospitalization, according to experts.

New formulations of the COVID vaccine are expected to specifically target omicron variants, and could potentially be available for distribution by next month.