CDC continues to track the evolution of SARS-CoV-2, including the Omicron variant and its descendants, using national genomic surveillance. This report summarizes U.S. trends in variant proportion estimates during May 2023-September 2024, a period when SARS-CoV-2 lineages primarily comprised descendants of Omicron variants XBB and JN.1. During summer and fall 2023, multiple descendants of XBB with immune escape substitutions emerged and reached >10% prevalence, including EG.5-like lineages by June 24, FL.1.5.1-like lineages by August 5, HV.1 lineage by September 30, and HK.3-like lineages by November 11. In winter 2023, the JN.1 variant emerged in the United States and rapidly attained predominance nationwide, representing a substantial genetic shift (>30 spike protein amino acid differences) from XBB lineages. Descendants of JN.1 subsequently circulated and reached >10% prevalence, including KQ.1-like and KP.2-like lineages by April 13, KP.3 and LB.1-like lineages by May 25, and KP.3.1.1 by July 20. Surges in COVID-19 cases occurred in winter 2024 during the shift to JN.1 predominance, as well as in summer 2023 and 2024 during circulation of multiple XBB and JN.1 descendants, respectively. The ongoing evolution of the Omicron variant highlights the importance of continued genomic surveillance to guide medical countermeasure development, including the selection of antigens for updated COVID-19 vaccines.

中文翻译：

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SARS-CoV-2 变体的基因组监测：Omicron XBB 和 JN.1 谱系的传播 - 美国，2023 年 5 月至 2024 年 9 月。


CDC 继续使用国家基因组监测来追踪 SARS-CoV-2 的演变，包括 Omicron 变体及其后代。本报告总结了 2023 年 5 月至 2024 年 9 月期间美国变体比例估计的趋势，在此期间，SARS-CoV-2 谱系主要由 Omicron 变体 XBB 和 JN.1 的后代组成。在 2023 年夏季和秋季，出现了具有免疫逃逸替换的 XBB 的多个后代，患病率达到 >10%，包括 6 月 24 日的 EG.5 样谱系、8 月 5 日的 FL.1.5.1 样谱系、9 月 30 日的 HV.1 谱系和 11 月 11 日的 HK.3 样谱系。2023 年冬季，JN.1 变体在美国出现，并迅速在全国范围内占据主导地位，代表着 XBB 谱系的重大遗传转变（>30 刺突蛋白氨基酸差异）。JN.1 的后代随后传播并达到 >10% 的患病率，包括 4 月 13 日的 KQ.1 样和 KP.2 样谱系，5 月 25 日的 KP.3 和 LB.1 样谱系，以及 7 月 20 日的 KP.3.1.1 谱系。COVID-19 病例激增发生在 2024 年冬季向 JN.1 为主的转变期间，以及 2023 年和 2024 年夏季多个 XBB 和 JN.1 后代的传播期间。Omicron 变体的持续演变凸显了持续基因组监测以指导医疗对策开发的重要性，包括为更新的 COVID-19 疫苗选择抗原。