T-6, Theoretical Biology and Biophysics, Los Alamos National Laboratory, Los Alamos, NM, USA.
Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
Nat Microbiol. 2022 May;7(5):640-652. doi: 10.1038/s41564-022-01105-z. Epub 2022 Apr 28.
The dynamics of SARS-CoV-2 replication and shedding in humans remain poorly understood. We captured the dynamics of infectious virus and viral RNA shedding during acute infection through daily longitudinal sampling of 60 individuals for up to 14 days. By fitting mechanistic models, we directly estimated viral expansion and clearance rates and overall infectiousness for each individual. Significant person-to-person variation in infectious virus shedding suggests that individual-level heterogeneity in viral dynamics contributes to 'superspreading'. Viral genome loads often peaked days earlier in saliva than in nasal swabs, indicating strong tissue compartmentalization and suggesting that saliva may serve as a superior sampling site for early detection of infection. Viral loads and clearance kinetics of Alpha (B.1.1.7) and previously circulating non-variant-of-concern viruses were mostly indistinguishable, indicating that the enhanced transmissibility of this variant cannot be explained simply by higher viral loads or delayed clearance. These results provide a high-resolution portrait of SARS-CoV-2 infection dynamics and implicate individual-level heterogeneity in infectiousness in superspreading.
人类对 SARS-CoV-2 复制和脱落的动力学仍知之甚少。我们通过对 60 个人进行长达 14 天的每日纵向采样，捕获了急性感染期间传染性病毒和病毒 RNA 脱落的动态。通过拟合机械模型，我们直接估计了每个个体的病毒扩张和清除率以及整体传染性。传染性病毒脱落的个体间存在显著差异，这表明病毒动力学的个体间异质性导致了“超级传播”。病毒基因组负荷在唾液中的峰值通常比在鼻腔拭子中早几天，这表明组织的强烈分隔，并表明唾液可能是早期检测感染的更好采样部位。Alpha（B.1.1.7）和以前流行的非关注变体病毒的病毒载量和清除动力学大多无法区分，这表明该变体的传染性增强不能仅仅用更高的病毒载量或延迟清除来解释。这些结果提供了 SARS-CoV-2 感染动力学的高分辨率图像，并暗示了传染性个体间的异质性在超级传播中的作用。
