Zhao R, Li M, Song H, et al. - As deaths among medical staff infected with SARS-CoV-2 virus could be prevented using a serologic assay for SARS-CoV-2-specific antibodies for serological surveillance of its infection at the early stage of disease, researchers sought to develop a COVID-19/SARS-CoV-2 S1 serology ELISA kit using CHO cell expressed full length SARS-CoV-2 S1 protein as capturing antigen. Further, they validated the ELISA kit with negative samples collected prior to the outbreaks or during the outbreak, and positive samples from patients confirmed with COVID-19. The ELISA kit had specificity of 97.5%, as examined against total 412 normal human samples, and sensitivity of 97.1%, as tested against 69 samples from hospitalized and/or recovered COVID-19 patients. Per outcomes, the developed assays can screen medical staff, in-coming patients, passengers and individuals who are in close contact with the confirmed cases to identify the “innocent viral spreaders”, protect the medical staff and check the further dissemination of the virus.