The SARS-CoV-2 pandemic is one of the most concerning health problems around the globe. We report the emergence of SARS-CoV-2 variant B.1.1.519 in Mexico City. This variant represented up to 90% of sequenced cases in February 2021. It is characterized by three amino acid changes in the spike protein: T478K, P681H, and T732A. We report the effective reproduction number of B.1.1.519 and present evidence of its geographical origin based on phylogenetic analysis. We also studied its evolution via haplotype analysis and identified the most recurrent haplotypes. Finally, we studied the clinical impact of B.1.1.519: patients infected with variant B.1.1.519 showed a highly significant adjusted odds ratio (aOR) increase of 1.85 over non-B.1.1.519 patients for developing a severe/critical outcome (P = 0.000296, 1.33–2.6 95% CI) and a 2.35-fold increase for hospitalization (P = 0.005, 1.32–4.34 95% CI). The continuous monitoring of this and other variants will be required to control the ongoing pandemic as it evolves.

中文翻译：

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SARS-CoV-2 变种 B.1.1.519 的进化格局及其在墨西哥城的临床影响

SARS-CoV-2 大流行是全球最令人担忧的健康问题之一。我们报告了 SARS-CoV-2 变种 B.1.1.519 在墨西哥城的出现。这种变异占 2021 年 2 月测序病例的 90%。它的特点是刺突蛋白的三个氨基酸变化：T478K、P681H 和 T732A。我们报告了 B.1.1.519 的有效繁殖数，并根据系统发育分析提供了其地理起源的证据。我们还通过单倍型分析研究了它的进化，并确定了最常见的单倍型。最后，我们研究了 B.1.1.519 的临床影响：感染变体 B.1.1.519 的患者在发展为严重/关键结果 (P = 0.000296, 1.33–2.6 95% CI) 和 2。住院治疗增加 35 倍（P = 0.005, 1.32–4.34 95% CI）。需要对这种和其他变体进行持续监测，以控制持续发展的流行病。