Genomic surveillance can lead to early identification of novel viral variants and inform pandemic response. Using this approach, we identified a new variant of the SARS-CoV-2 virus that emerged in the United States (U.S.). The earliest sequenced genomes of this variant, referred to as 20C-US, can be traced to Texas in late May of 2020. This variant circulated in the U.S. uncharacterized for months and rose to recent prevalence during the third pandemic wave. It initially acquired five novel, relatively unique non-synonymous mutations. 20C-US is continuing to acquire multiple new mutations, including three independently occurring spike protein mutations. Monitoring the ongoing evolution of 20C-US, as well as other novel emerging variants, will be essential for understanding SARS-CoV-2 host adaptation and predicting pandemic outcomes.

中文翻译：

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在美国流行的新SARS-CoV-2变体的出现和演变

基因组监测可导致及早发现新型病毒变异并告知大流行反应。使用这种方法，我们确定了在美国（US）出现的SARS-CoV-2病毒的新变种。该变体的最早测序基因组被称为20C-US，可追溯到2020年5月下旬到德克萨斯州。该变体在美国传播了数月，但没有特征化，并在第三次大流行浪潮中上升到最近的流行。它最初获得了五个新颖的，相对独特的非同义突变。20C-US正在继续获得多个新突变，包括三个独立发生的刺突蛋白突变。监测20C-US以及其他新出现的变体的持续发展，对于理解SARS-CoV-2宿主的适应性和预测大流行的结果至关重要。