Division of Systems Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan; Faculty of Medicine, Kobe University, Kobe, Japan.
Division of Systems Virology, Department of Microbiology and Immunology, The Institute of Medical Science, The University of Tokyo, Tokyo, Japan.
Cell. 2022 Jun 9;185(12):2103-2115.e19. doi: 10.1016/j.cell.2022.04.035. Epub 2022 May 2.
Soon after the emergence and global spread of the SARS-CoV-2 Omicron lineage BA.1, another Omicron lineage, BA.2, began outcompeting BA.1. The results of statistical analysis showed that the effective reproduction number of BA.2 is 1.4-fold higher than that of BA.1. Neutralization experiments revealed that immunity induced by COVID vaccines widely administered to human populations is not effective against BA.2, similar to BA.1, and that the antigenicity of BA.2 is notably different from that of BA.1. Cell culture experiments showed that the BA.2 spike confers higher replication efficacy in human nasal epithelial cells and is more efficient in mediating syncytia formation than the BA.1 spike. Furthermore, infection experiments using hamsters indicated that the BA.2 spike-bearing virus is more pathogenic than the BA.1 spike-bearing virus. Altogether, the results of our multiscale investigations suggest that the risk of BA.2 to global health is potentially higher than that of BA.1.
奥密克戎变异株 BA.1 出现并在全球传播后不久，另一种奥密克戎变异株 BA.2 开始取代 BA.1。统计分析结果表明，BA.2 的有效繁殖数比 BA.1 高 1.4 倍。中和实验表明，广泛接种于人群的 COVID 疫苗诱导的免疫对 BA.2 无效，与 BA.1 相似，且 BA.2 的抗原性明显不同于 BA.1。细胞培养实验表明，BA.2 的刺突蛋白在人鼻腔上皮细胞中的复制效率更高，介导合胞体形成的效率也高于 BA.1 的刺突蛋白。此外，使用仓鼠进行的感染实验表明，携带 BA.2 刺突的病毒比携带 BA.1 刺突的病毒具有更高的致病性。总之，我们多尺度研究的结果表明，BA.2 对全球健康的威胁可能比 BA.1 更高。
