Zou Jing, Xia Hongjie, Xie Xuping, Kurhade Chaitanya, Machado Rafael R G, Weaver Scott C, Ren Ping, Shi Pei-Yong
Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA.
Departments of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX, USA.
Nat Commun. 2022 Feb 9;13(1):852. doi: 10.1038/s41467-022-28544-w.
The spread of the Omicron SARS-CoV-2 variant underscores the importance of analyzing the cross-protection from previous non-Omicron infection. We have developed a high-throughput neutralization assay for Omicron SARS-CoV-2 by engineering the Omicron spike gene into an mNeonGreen USA-WA1/2020 SARS-CoV-2 (isolated in January 2020). Using this assay, we determine the neutralization titers (defined as the maximal serum dilution that inhibited 50% of infectious virus) of patient sera collected at 1- or 6-months after infection with non-Omicron SARS-CoV-2. From 1- to 6-month post-infection, the neutralization titers against USA-WA1/2020 decrease from 601 to 142 (a 4.2-fold reduction), while the neutralization titers against Omicron-spike SARS-CoV-2 remain low at 38 and 32, respectively. Thus, at 1- and 6-months after non-Omicron SARS-CoV-2 infection, the neutralization titers against Omicron are 15.8- and 4.4-fold lower than those against USA-WA1/2020, respectively. The low cross-neutralization against Omicron from previous non-Omicron infection supports vaccination of formerly infected individuals to mitigate the health impact of the ongoing Omicron surge.
奥密克戎 SARS-CoV-2 变体的传播凸显了分析既往非奥密克戎感染所产生的交叉保护作用的重要性。我们通过将奥密克戎刺突基因工程改造到一株 mNeonGreen USA-WA1/2020 SARS-CoV-2（于2020年1月分离）中，开发了一种针对奥密克戎 SARS-CoV-2 的高通量中和试验。利用该试验，我们测定了非奥密克戎 SARS-CoV-2 感染后1个月或6个月采集的患者血清的中和滴度（定义为抑制50%感染性病毒的最大血清稀释度）。感染后1至6个月，针对 USA-WA1/2020 的中和滴度从601降至142（降低了4.2倍），而针对奥密克戎刺突 SARS-CoV-2 的中和滴度分别维持在较低水平38和32。因此，在非奥密克戎 SARS-CoV-2 感染后的1个月和6个月，针对奥密克戎的中和滴度分别比对 USA-WA1/2020 的中和滴度低15.8倍和4.4倍。既往非奥密克戎感染对奥密克戎的交叉中和作用较低，这支持对既往感染者进行疫苗接种，以减轻当前奥密克戎激增对健康的影响。
