Elucidating Airborne SARS-CoV-2 Infectivity at Single Aerosol Resolution

项目总结 在这一紧急的R21努力中，我们建议实施一系列新的研究，旨在改善我们的 对SARS-CoV-2空气生物学有基本了解。通过理论、实验、 和流行病学数据，越来越多的人达成共识，认为呼吸气溶胶在 新冠肺炎的传播。然而，尽管了解基本机制很重要， SARS-CoV-2空气生物学涉及的一些基本问题 仍未得到答复。特别是SARS-CoV-2粒子在不同气溶胶中的分布 还没有对种群进行详细的研究，也没有数据来预测病毒的生存能力和传染性。 不同气溶胶种群中的单个空气传播病毒颗粒。此外，目前尚不清楚 病毒倾向于均匀地分布在给定的气溶胶种群中还是聚集在一个小的 气溶胶小滴的数量，这是了解新冠肺炎感染量的一个基本问题 变速箱。为了应对这些挑战，我们提出了一种结合有效采样的新的分析方法 呼气，气溶胶集合的高分辨率分馏，以及非活动和非活动的耦合分析 通过RT-PCR和病毒空斑相结合的方法收集气溶胶部分中的感染性病毒颗粒 化验。值得注意的是，气溶胶分级将使用空气动力学气溶胶分类器作为 分离单分散气溶胶种群的独特技术。此外，一种新的离散化技术 收集的气溶胶颗粒将使用用于气溶胶沉积的热响应水凝胶来实施， 允许将颗粒输送到细胞培养中，同时保持空间隔离并阐明病毒 在给定的粒度分数内的分布和聚集。合并的数据集产生于拟议的 研究将初步了解SARS-CoV-2在呼吸气溶胶中的分布和构象， 以及气溶胶特性(大小、病毒含量、病毒分布和聚集)与 下游传染性。我们预计，对雾化病毒传染性的更好理解正在出现 这些研究将阐明新冠肺炎空中传播的基本方面，并使我们能够识别 与SARS-CoV-2相关的感染量，从而支持对传播的准确建模 个人防护用品、房间通风和卫生协议的动态和指导性改进建议，以增强 进行干预，最大限度地减少病毒的传播。

PROJECT SUMMARY In this emergency R21 effort we propose to implement a set of novel studies designed to improve our fundamental understanding of SARS-CoV-2 aerobiology. Through a combination of theoretical, experimental, and epidemiological data, there is emerging consensus that respiratory aerosols play a primary role in the transmission of COVID-19. However, despite the importance of understanding the fundamental mechanisms involved in the airborne transmission route, a number of basic questions central to SARS-CoV-2 aerobiology remain unanswered. In particular, the distribution of SARS-CoV-2 particles within different aerosol size populations has not yet been studied in detail, nor is there data available to predict the viability and infectivity of individual airborne virus particles within different aerosol populations. Furthermore, it is not currently known whether the virus tends to be uniformly distributed within a given aerosol population or clustered within a small number of aerosol droplets, an essential question for understanding the quantum of infection for COVID-19 transmission. To address these challenges, we propose a novel analytical approach combining efficient sampling of exhaled breath, high resolution fractionation of aerosol ensembles, and coupled analysis of inactive and infective virus particles within the collected aerosol fractions through a combination of RT-PCR and viral plaque assays. Significantly, aerosol fractionation will be performed using an Aerodynamic Aerosol Classifier as a unique technology for isolating monodisperse aerosol populations. In addition, a new technique for discretizing the collected aerosol particles will be implemented using a thermo-responsive hydrogel for aerosol deposition, allowing the particles to be delivered to cell culture while remaining spatially isolated and elucidating virus distribution and clustering within a given size fraction. The combined data sets resulting from the proposed studies will provide a first view of the distribution and conformation of SARS-CoV-2 within respiratory aerosols, and the relationships between aerosol properties (size, virus content, virus distribution, and clustering) and downstream infectivity. We anticipate that the improved understanding of aerosolized virus infectivity emerging from these studies will illuminate fundamental aspects of COVID-19 airborne transmission and allow us to identify the quantum of infection associated with SARS-CoV-2, thus supporting accurate modeling of transmission dynamics and guiding improved recommendations for PPE, room ventilation, and sanitation protocols to enhance intervention and minimize transmission of the virus.