New Covid-19 variants are spreading around the world and stoking fears of a summer surge in cases n the US, in the latest sign of the infectious disease’s ability to mutate and potentially threaten collective immunity.
KP. 2, one of several so-called FLiRT variants — the word derives from the names of the mutations in the variants’ genetic code — has become the dominant coronavirus strain in the US since first emerging in March.
In the two weeks to May 11, KP. 2 accounted for 28.2 per cent of cases, up from just 3.8 per cent in the two weeks to the end of March, according to the latest data from the US Centers for Disease Control and Prevention. The KP1.1 variant has also grown rapidly to account for 7.6 per cent of infections.
您已閱讀19%（737字），剩余81%（3093字）包含更多重要信息，訂閱以繼續(xù)探索完整內(nèi)容，并享受更多專(zhuān)屬服務(wù)。