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

项目摘要 在这项紧急的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空气生物学的基本了解。通过结合理论，实验， 和流行病学数据，有一个正在形成的共识，即呼吸气溶胶发挥主要作用， 传播COVID-19。然而，尽管了解基本机制的重要性 涉及空气传播途径，一些基本问题的核心SARS-CoV-2空气生物学 仍然没有答案。特别是，SARS-CoV-2颗粒在不同气溶胶尺寸内的分布 人群尚未进行详细研究，也没有数据可以预测的生存能力和传染性， 不同气溶胶群体中的单个空气传播病毒颗粒。此外，目前还不知道 病毒是否倾向于均匀分布在给定的气溶胶群体中或聚集在小的气溶胶群体中， 气溶胶液滴的数量，这是了解COVID-19感染量的一个基本问题 传输为了解决这些挑战，我们提出了一种新的分析方法，结合有效的采样 的呼出气，气溶胶集合的高分辨率分馏，以及非活性和 通过RT-PCR和病毒空斑的组合，在收集的气溶胶组分中检测感染性病毒颗粒 测定。值得注意的是，气溶胶分级将使用空气动力学气溶胶分级器作为 分离单分散气溶胶群体的独特技术。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现， 允许颗粒被递送到细胞培养物中，同时保持空间分离并阐明病毒 在给定的尺寸分数内的分布和聚类。根据拟议的 这些研究将提供SARS-CoV-2在呼吸气溶胶中的分布和构象的第一个视图， 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，对雾化病毒感染性的进一步了解将出现 这些研究将阐明COVID-19空气传播的基本方面，并使我们能够识别 与SARS-CoV-2相关的感染量，从而支持准确的传播模型 动态和指导PPE，房间通风和卫生协议的改进建议，以提高 采取干预措施，尽量减少病毒的传播。

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.