Abstract
Serological testing of large representative populations for antibodies to SARS-CoV-2 is needed to estimate seroprevalence, transmission dynamics, and the duration of antibody responses from natural infection and vaccination. In this study, a high-throughput SARS-CoV-2 multiplex microsphere immunoassay (MMIA) was developed for the receptor binding domain (RBD) and nucleocapsid (N) that was more sensitive than enzyme-linked immunosorbent assay (ELISA) (98% versus 87%). The MMIA was then applied and validated in 264 first responders in Colorado using serum and dried blood spot (DBS) eluates, compared to ELISA, and evaluated for neutralizing antibodies. Four percent (11/264) of first responders were seropositive in July to August 2020. Serum and DBS were highly correlated for anti-RBD and anti-N antibodies ( R = 0.83, P < 0.0001 and R = 0.87, P < 0.0001, respectively) by MMIA. The MMIA accurately predicted SARS-CoV-2 neutralizing antibodies using DBS ( R = 0.76, P = 0.037). On repeat antibody testing 3 months later, anti-RBD IgG decreased less rapidly than anti-N IgG measured by MMIA, with a median change in geometric median fluorescence intensity of 62% versus 79% ( P < 0.01) for anti-RBD and anti-N IgG, respectively. This novel MMIA using DBS could be scalable for rapid and affordable SARS-CoV-2 serosurveillance in the United States and globally.
Keywords: COVID-19 antibody testing; SARS-CoV-2 infection serological testing; dried blood spot testing; enzyme immunoassay; immunological surveillance.
【저자키워드】 enzyme immunoassay, COVID-19 antibody testing, SARS-CoV-2 infection serological testing, dried blood spot testing, immunological surveillance., 【초록키워드】 SARS-CoV-2, Antibody testing, vaccination, Neutralizing antibodies, antibody, SARS-COV-2 infection, Antibody Response, Seroprevalence, ELISA, Population, Receptor binding domain, immunoassay, serum, enzyme-linked immunosorbent assay, Antibody responses, Serological testing, nucleocapsid, RBD, anti-N antibodies, Transmission dynamics, enzyme immunoassay, COVID-19 antibody, United States, Responder, multiplex, natural infection, serological, seropositive, SARS-CoV-2 neutralizing antibodies, Blood, microsphere, SARS-CoV-2 neutralizing antibody, first responders, anti-N IgG, anti-RBD, Anti-RBD IgG, Immunological Surveillance, enzyme, RBD IgG, enzyme-linked immunosorbent, fluorescence intensity, predicted, the United State, evaluated, applied, median, less, correlated, anti-N antibody, geometric, 【제목키워드】 SARS-CoV-2, validation, USA, application, development, first responders, spot,