State Key Laboratory of Emerging Infectious Diseases, Department of Microbiology, Carol Yu Centre for Infection, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China; Department of Infectious Disease and Microbiology, The University of Hong Kong-Shenzhen Hospital, Shenzhen, Guangdong Province, China; Centre for Virology, Vaccinology and Therapeutics, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China; Academician Workstation of Hainan Province, Hainan Medical University-The University of Hong Kong Joint Laboratory of Tropical Infectious Diseases, Hainan Medical University, Haikou, Hainan, China; Department of Microbiology, Queen Mary Hospital, Pokfulam, Hong Kong Special Administrative Region, China; Guangzhou Laboratory, Guangdong Province, China.
State Key Laboratory of Emerging Infectious Diseases, Department of Microbiology, Carol Yu Centre for Infection, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.
Cell Rep Med. 2022 Sep 20;3(9):100743. doi: 10.1016/j.xcrm.2022.100743. Epub 2022 Aug 29.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron BA.2 was a dominant circulating SARS-CoV-2 variant worldwide. Recent reports hint that BA.2 is similarly potent regarding antibody evasion but may be more transmissible than BA.1. The pathogenicity of BA.2 remains unclear and is of critical public health significance. Here we investigated the virological features and pathogenicity of BA.2 with in vitro and in vivo models. We show that BA.2 is less dependent on transmembrane protease serine 2 (TMPRSS2) for virus entry in comparison with BA.1 in vitro. In K18-hACE2 mice, BA.2 replicates more efficiently than BA.1 in the nasal turbinates and replicates marginally less efficiently in the lungs, leading to decreased body weight loss and improved survival. Our study indicates that BA.2 is similarly attenuated in lungs compared with BA.1 but is potentially more transmissible because of its better replication at the nasal turbinates.
严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）奥密克戎 BA.2 是一种在全球范围内占主导地位的 SARS-CoV-2 变体。最近的报告表明，BA.2 在逃避抗体方面同样有效，但可能比 BA.1 更具传染性。BA.2 的致病性仍不清楚，这对公共卫生具有重要意义。在这里，我们使用体外和体内模型研究了 BA.2 的病毒学特征和致病性。我们表明，与 BA.1 相比，BA.2 在体外对跨膜蛋白酶丝氨酸 2（TMPRSS2）的依赖性较低。在 K18-hACE2 小鼠中，BA.2 在鼻甲骨中的复制效率比 BA.1 更高，而在肺部中的复制效率略低，导致体重减轻减少和存活率提高。我们的研究表明，与 BA.1 相比，BA.2 在肺部的减毒程度相似，但由于在鼻甲骨中更好的复制，其传播潜力可能更大。
