State Key Laboratory of Emerging Infectious Diseases, Carol Yu Centre for Infection, Department of Microbiology, School of Clinical Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong Special Administrative Region, China.
Key Laboratory of Tropical Translational Medicine of Ministry of Education, Hainan Medical University, Haikou, Hainan, China.
Science. 2022 Jul 22;377(6604):428-433. doi: 10.1126/science.abn8939. Epub 2022 Jun 23.
The in vivo pathogenicity, transmissibility, and fitness of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron (B.1.1.529) variant are not well understood. We compared these virological attributes of this new variant of concern (VOC) with those of the Delta (B.1.617.2) variant in a Syrian hamster model of COVID-19. Omicron-infected hamsters lost significantly less body weight and exhibited reduced clinical scores, respiratory tract viral burdens, cytokine and chemokine dysregulation, and lung damage than Delta-infected hamsters. Both variants were highly transmissible through contact transmission. In noncontact transmission studies Omicron demonstrated similar or higher transmissibility than Delta. Delta outcompeted Omicron without selection pressure, but this scenario changed once immune selection pressure with neutralizing antibodies-active against Delta but poorly active against Omicron-was introduced. Next-generation vaccines and antivirals effective against this new VOC are therefore urgently needed.
我们在 COVID-19 的叙利亚仓鼠模型中比较了这种新的关注变体（VOC）与 Delta（B.1.617.2）变体的这些病毒学特性。与感染 Delta 的仓鼠相比，感染奥密克戎的仓鼠体重明显减轻，临床评分降低，呼吸道病毒载量、细胞因子和趋化因子失调以及肺部损伤减少。两种变体都具有很高的通过接触传播的能力。在非接触传播研究中，奥密克戎的传播能力与德尔塔相似或更高。在没有免疫选择压力的情况下，Delta 胜过奥密克戎，但一旦引入针对 Delta 具有中和抗体活性但对奥密克戎活性差的免疫选择压力，这种情况就会改变。因此，迫切需要针对这种新的 VOC 的下一代疫苗和抗病毒药物。
