Mok Bobo Wing-Yee, Liu Honglian, Deng Shaofeng, Liu Jiayan, Zhang Anna Jinxia, Lau Siu-Ying, Liu Siwen, Tam Rachel Chun-Yee, Cremin Conor J, Ng Timothy Ting-Leung, Leung Jake Siu-Lun, Lee Lam-Kwong, Wang Pui, To Kelvin Kai-Wang, Chan Jasper Fuk-Woo, Chan Kwok-Hung, Yuen Kwok-Yung, Siu Gilman Kit-Hang, Chen Honglin
Department of Microbiology and State Key Laboratory for Emerging Infectious Diseases, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
Department of Health Technology and Informatics, Faculty of Health and Social Sciences, The Hong Kong Polytechnic University, Hong Kong SAR, China.
Commun Biol. 2021 Sep 20;4(1):1102. doi: 10.1038/s42003-021-02640-x.
Emerging variants of SARS-CoV-2 have been shown to rapidly replace original circulating strains in humans soon after they emerged. There is a lack of experimental evidence to explain how these natural occurring variants spread more efficiently than existing strains of SARS-CoV-2 in transmission. We found that the Alpha variant (B.1.1.7) increased competitive fitness over earlier parental D614G lineages in in-vitro and in-vivo systems. Using hamster transmission model, we further demonstrated that the Alpha variant is able to replicate and shed more efficiently in the nasal cavity of hamsters than other variants with low dose and short duration of exposure. The capability to initiate effective infection with low inocula may be one of the key factors leading to the rapid transmission of emerging variants of SARS-CoV-2.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的新出现变种在出现后不久就已显示出能迅速取代人类中最初流行的毒株。目前缺乏实验证据来解释这些自然出现的变种在传播过程中如何比SARS-CoV-2的现有毒株更有效地传播。我们发现，在体外和体内系统中，阿尔法变种（B.1.1.7）比早期的亲本D614G谱系具有更高的竞争适应性。使用仓鼠传播模型，我们进一步证明，与其他变种相比，阿尔法变种在低剂量和短暴露时间的情况下，能够在仓鼠鼻腔中更有效地复制和排出。以低接种量引发有效感染的能力可能是导致SARS-CoV-2新出现变种迅速传播的关键因素之一。
