A new group of COVID-19 variants called "FLiRT" are spreading in the United States and driving an increasing proportion of cases, sparking concerns about a potential summer wave. The FLiRT strains — KP.2, KP.
1.1, and KP.3 — now account for more than half of COVID-19 cases nationwide, according to the latest data from .
These new variants, which scientists nicknamed "FLiRT" after their mutations, have been circulating in the U.S. since the early spring.
In April, KP.2 quickly overtook that drove a , to become the dominant strain in the U.S.
Currently, KP.2 accounts for over a quarter of infections nationwide, according to the CDC. During a two-week period ending on May 25, KP.
2 made up an estimated 28.5% of cases in the U.S.
, up from about 6% in mid-April and just 1% in mid-March. After KP.2, the next most common variant is KP.
3, another FLiRT variant, which accounts for 12.7% of cases. It's followed by JN.
1.7, a JN.1 subvariant, and another FLiRT variant, KP.
1.1, which each account for 9.2% of cases.
Together, KP.2, KP.3 and KP.
1.1 account for just over 50% of cases. Although hospitalizations are down and the country appears to be in a COVID-19 lull, there has been a small uptick in test positivity and emergency room visits, per CDC data.
These trends, along with previous summer waves, have stoked fears about a surge of infections this summer. Scientists are warning that the FLiRT variants may be better at evading the immune system due to their spike protein mutations, an.
