A group of new COVID-19 variants, collectively known as FLiRT, has emerged from Omicron's JN.1 lineage, spreading rapidly in the US. Led by the dominant strain KP.2, FLiRT variants are more infectious but exhibit largely unchanged symptoms. The term "FLiRT" stems from their mutations. KP.2 accounts for 25% of new cases, raising concerns about a potential summer surge.