Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA; UCSF-Abbott Viral Diagnostics and Discovery Center, San Francisco, CA, USA.
Gladstone Institute of Data Science and Biotechnology, San Francisco, CA, USA; Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA.
Cell. 2022 Apr 28;185(9):1539-1548.e5. doi: 10.1016/j.cell.2022.03.019. Epub 2022 Mar 18.
Virus-like particle (VLP) and live virus assays were used to investigate neutralizing immunity against Delta and Omicron SARS-CoV-2 variants in 259 samples from 128 vaccinated individuals. Following Delta breakthrough infection, titers against WT rose 57-fold and 3.1-fold compared with uninfected boosted and unboosted individuals, respectively, versus only a 5.8-fold increase and 3.1-fold decrease for Omicron breakthrough infection. Among immunocompetent, unboosted patients, Delta breakthrough infections induced 10.8-fold higher titers against WT compared with Omicron (p = 0.037). Decreased antibody responses in Omicron breakthrough infections relative to Delta were potentially related to a higher proportion of asymptomatic or mild breakthrough infections (55.0% versus 28.6%, respectively), which exhibited 12.3-fold lower titers against WT compared with moderate to severe infections (p = 0.020). Following either Delta or Omicron breakthrough infection, limited variant-specific cross-neutralizing immunity was observed. These results suggest that Omicron breakthrough infections are less immunogenic than Delta, thus providing reduced protection against reinfection or infection from future variants.
病毒样颗粒 (VLP) 和活病毒检测被用于研究 128 名接种个体的 259 个样本中的针对 Delta 和奥密克戎 SARS-CoV-2 变体的中和免疫。在突破 Delta 感染后，与未感染加强和未加强个体相比，针对 WT 的滴度分别升高了 57 倍和 3.1 倍，而奥密克戎突破感染仅升高了 5.8 倍和 3.1 倍。在免疫功能正常、未加强的患者中，Delta 突破感染引起的针对 WT 的滴度比奥密克戎高 10.8 倍（p=0.037）。与 Delta 相比，奥密克戎突破感染中的抗体反应下降可能与更高比例的无症状或轻症突破感染有关（分别为 55.0%和 28.6%），与中重度感染相比，针对 WT 的滴度低 12.3 倍（p=0.020）。在 Delta 或奥密克戎突破感染后，观察到有限的变体特异性交叉中和免疫。这些结果表明，奥密克戎突破感染的免疫原性低于 Delta，从而降低了对再次感染或未来变体感染的保护作用。
