Department of Microbiology and Molecular Medicine, University of Geneva, Geneva, Switzerland.
Division of Infectious Diseases, Geneva University Hospitals, Geneva, Switzerland.
Nat Commun. 2022 Jul 4;13(1):3840. doi: 10.1038/s41467-022-31556-1.
Emerging SARS-CoV-2 variants raise questions about escape from previous immunity. As the population immunity to SARS-CoV-2 has become more complex due to prior infections with different variants, vaccinations or the combination of both, understanding the antigenic relationship between variants is needed. Here, we have assessed neutralizing capacity of 120 blood specimens from convalescent individuals infected with ancestral SARS-CoV-2, Alpha, Beta, Gamma or Delta, double vaccinated individuals and patients after breakthrough infections with Delta or Omicron-BA.1. Neutralization against seven authentic SARS-CoV-2 isolates (B.1, Alpha, Beta, Gamma, Delta, Zeta and Omicron-BA.1) determined by plaque-reduction neutralization assay allowed us to map the antigenic relationship of SARS-CoV-2 variants. Highest neutralization titers were observed against the homologous variant. Antigenic cartography identified Zeta and Omicron-BA.1 as separate antigenic clusters. Substantial immune escape in vaccinated individuals was detected for Omicron-BA.1 but not Zeta. Combined infection/vaccination derived immunity results in less Omicron-BA.1 immune escape. Last, breakthrough infections with Omicron-BA.1 lead to broadly neutralizing sera.
新出现的 SARS-CoV-2 变体引发了对先前免疫逃逸的质疑。由于先前感染不同变体、接种疫苗或两者结合导致人群对 SARS-CoV-2 的免疫力变得更加复杂，因此需要了解变体之间的抗原关系。在这里，我们评估了 120 份来自感染 SARS-CoV-2 原始株、Alpha、Beta、Gamma 或 Delta 的康复个体、双重接种个体以及感染 Delta 或 Omicron-BA.1 突破性感染患者的血液标本的中和能力。通过噬斑减少中和试验确定对七种真实 SARS-CoV-2 分离株（B.1、Alpha、Beta、Gamma、Delta、Zeta 和 Omicron-BA.1）的中和能力使我们能够绘制 SARS-CoV-2 变体的抗原关系图。观察到针对同源变体的最高中和滴度。抗原绘图将 Zeta 和 Omicron-BA.1 确定为单独的抗原簇。在接种疫苗的个体中检测到针对 Omicron-BA.1 的大量免疫逃逸，但对 Zeta 则不然。联合感染/接种疫苗产生的免疫力导致 Omicron-BA.1 的免疫逃逸减少。最后，Omicron-BA.1 的突破性感染导致广泛中和的血清。
