AFS/SERS Saliva-Based SARS-CoV-2 Earliest Infection and Antibodies Detection

Background: The NIH Common Fund Extracellular RNA Communication (ERC) Program funded this study as a response to the need for new or non-traditional technologies developed for single extracellular vesicle, exosome and extracellular RNA (exRNA) isolation, and analyze and reposition them for detection of SARS-CoV-2.

Materials/Methods: The study enrolled participants in the University of California, Los Angeles area, who had recovered from SARS-CoV-2, who were vaccinated for COVID-19, or had both conditions. Antibody responses, cellular immune responses, and the ability of their sera to neutralize the virus were characterized. In addition, the participants completed responses to detailed questionnaires about their clinical course with SARS-CoV-2 infection, and other medical data and specimens (blood, saliva) were collected. Serologic assays were run to understand the breadth (IgA, IgG, IgM) and duration of the antibody response. Cellular immune response assays and viral neutralization assays were also performed.

Outcome/Impact: Study results included aggregate antibody results. A quantitative non-invasive saliva based SARS-CoV-2 antibody test was developed and validated with sufficient specificity to be useful for population-based monitoring and monitoring of individuals following vaccination.

背景：本研究由美国国立卫生研究院（National Institutes of Health, NIH）共同基金的细胞外RNA通讯（Extracellular RNA Communication, ERC）项目资助，旨在响应针对单个细胞外囊泡（extracellular vesicle）、外泌体（exosome）及细胞外RNA（exRNA）分离的新型或非传统技术的研发需求，并对这些技术进行分析与重新定位，以用于严重急性呼吸综合征冠状病毒2（SARS-CoV-2）的检测。
材料与方法：本研究招募了加州大学洛杉矶分校辖区内的受试者，这些受试者要么曾感染严重急性呼吸综合征冠状病毒2（SARS-CoV-2）并康复，要么已接种新型冠状病毒肺炎（COVID-19）疫苗，或兼具两种情况。研究对受试者的抗体应答、细胞免疫应答以及血清中和病毒的能力进行了表征。此外，受试者需填写关于严重急性呼吸综合征冠状病毒2（SARS-CoV-2）感染临床病程的详细问卷，研究人员同时收集了其他医学数据及血液、唾液等生物标本。通过血清学检测，明确了抗体应答的广度（免疫球蛋白A（IgA）、免疫球蛋白G（IgG）、免疫球蛋白M（IgM））与持续时间。此外还开展了细胞免疫应答检测及病毒中和试验。
结果与影响：本研究结果涵盖了汇总抗体检测数据。研究开发并验证了一种基于唾液的定量非侵入性严重急性呼吸综合征冠状病毒2（SARS-CoV-2）抗体检测方法，该方法具备足够的特异性，可用于人群监测以及疫苗接种后个体的健康监测。