SARS-CoV-2 Variant Proportions

To identify and track SARS-CoV-2 variants, CDC uses genomic surveillance. CDC's national genomic surveillance system collects SARS-CoV-2 specimens for sequencing through the National SARS-CoV-2 Strain Surveillance (NS3) program, as well as SARS-CoV-2 sequences generated by commercial or academic laboratories contracted by CDC and state or local public health laboratories. Viral genomic sequences are analyzed and classified as a particular variant. The proportions of variants in a population are estimated nationally, by HHS region, and by jurisdiction. The thousands of sequences analyzed every week through CDC’s national genomic sequencing and bioinformatics efforts fuel this comprehensive and population-based U.S. surveillance system established to identify and monitor the spread of variants.

These data appear on the CDC COVID Data Tracker at the following URL: <a href="https://covid.cdc.gov/covid-data-tracker/#variant-proportions">https://covid.cdc.gov/covid-data-tracker/#variant-proportions</a>

For more information on how these data are generated and used to provide estimates of variant proportions, please see the following references:

<ul>
<li>Paul P, France AM, Aoki Y, et al. Genomic Surveillance for SARS-CoV-2 Variants Circulating in the United States, December 2020–May 2021. MMWR Morb Mortal Wkly Rep 2021;70:846–850. DOI: <a href="http://dx.doi.org/10.15585/mmwr.mm7023a3">http://dx.doi.org/10.15585/mmwr.mm7023a3</a></li>
<li>Lambrou AS, Shirk P, Steele MK, et al. Genomic Surveillance for SARS-CoV-2 Variants: Predominance of the Delta (B.1.617.2) and Omicron (B.1.1.529) Variants — United States, June 2021–January 2022. MMWR Morb Mortal Wkly Rep 2022;71:206–211. DOI: <a href="http://dx.doi.org/10.15585/mmwr.mm7106a4">http://dx.doi.org/10.15585/mmwr.mm7106a4</a></li></ul>

为识别和追踪SARS-CoV-2变异株，美国疾病控制与预防中心（CDC）采用基因组监测策略。CDC的国家基因组监测系统通过国家SARS-CoV-2株监测计划（NS3）收集SARS-CoV-2样本进行测序，同时亦收集由CDC委托的商业或学术实验室以及州或地方公共卫生实验室生成的SARS-CoV-2序列。病毒基因组序列经过分析并归类为特定变异株。在全国范围内，根据美国卫生与公众服务部（HHS）的区域划分以及行政区域，估算变异株在人群中的比例。每周通过CDC的国家基因组测序和生物信息学努力，对数千个序列进行分析，以此支撑这一综合性的以人群为基础的美国监测系统，该系统旨在识别和监控变异株的传播。相关数据可在以下网址的CDC COVID数据追踪器中查看：<a href="https://covid.cdc.gov/covid-data-tracker/#variant-proportions">https://covid.cdc.gov/covid-data-tracker/#variant-proportions</a>。关于如何生成这些数据及其在提供变异株比例估计中的应用，请参阅以下参考文献：<ul><li>Paul P, France AM, Aoki Y, et al. Genomic Surveillance for SARS-CoV-2 Variants Circulating in the United States, December 2020–May 2021. MMWR Morb Mortal Wkly Rep 2021;70:846–850. DOI: <a href="http://dx.doi.org/10.15585/mmwr.mm7023a3">http://dx.doi.org/10.15585/mmwr.mm7023a3</a></li><li>Lambrou AS, Shirk P, Steele MK, et al. Genomic Surveillance for SARS-CoV-2 Variants: Predominance of the Delta (B.1.617.2) and Omicron (B.1.1.529) Variants — United States, June 2021–January 2022. MMWR Morb Mortal Wkly Rep 2022;71:206–211. DOI: <a href="http://dx.doi.org/10.15585/mmwr.mm7106a4">http://dx.doi.org/10.15585/mmwr.mm7106a4</a></li></ul>