Although the omicron subvariant BA.5 has been the predominant strain of COVID in the United States for some months, at least four other subvariants have been gaining ground over the past few weeks.
The BA.5 subvariant is still responsible for 84.8% of COVID cases in the United States, according to the CDC’s most recent figures, released on Tuesday.
This subvariant, which has been the predominant strain of COVID in the United States since early July, reached an all-time high of over 90% of cases, but has now began to fall as at least four other forms of omicron begin to circulate within the population.
For the first time, one of these strains, the BA.4.6 subvariant, is responsible for more than 10% of COVID cases in the United States. The subvariant, which has been circulating since at least the beginning of June, currently accounts for 10.3% of cases and is gradually gaining momentum while its parent strain BA.4 continues to drop.
This BA.4 subvariant is still the third-most prevalent in the United States, accounting for an estimated 1.8% of cases, but the CDC is keeping a close check on the emergence of two other subvariants ahead of the autumn and winter seasons.
According to the CDC, the BF.7 subvariant is actually a sublineage of BA.5. Its official name is BA.220.127.116.11, however in reporting documents, scientists have reduced it to BF.7.
Scientists continue to monitor this subvariant, which accounts for 1.7% of cases, because it has now exceeded another sublineage of omicron, BA.2.75, in terms of instances.
According to Fortune magazine, Belgium, Denmark, Germany, and France are currently experiencing an increase in BF.7 cases.
Scientists are also observing whether the BF.7 subvariant behaves differently than BA.5, but all omicron strains share similar characteristics, including an increased capacity to circumvent preexisting immunity from previous infections and an increased capacity to avoid immunity conveyed by vaccinations.
It is currently unknown how effective the newly developed bivalent COVID vaccines, which were designed to target omicron subvariants, will be against BF.7.