Infectious diseases are among the leading causes of mortality worldwide. A new coronavirus named severe acute respiratory syndrome corona virus 2 (SARS-CoV-2) was identified in Wuhan, China in SARS-CoV-2 Antibodies. To support COVID-19 research, Sino Biological has developed a large collection of antibodies against different antigens of SARS-CoV-2. These antibodies can be used to detect and/or neutralize the virus in a variety of assays including ELISA, western blot, Immunofluorescent staining, Immunohistochemistry, SPR (Biacore and Introduction. Following the global spread of SARS-CoV-2 and the subsequent emergence of more pathogenic variants, the need for population serosurveillance became urgent to track the course of virus-specific immune responses as a tool for estimating population susceptibility to emerging variants, and informing public health policy about vaccination, immune-surveillance and intervention In 163 samples, which showed 5.0 AU/mL or more titers of YHLO IgM or YHLO IgG, we measured Elecsys Anti-SARS-CoV-2 Ig (Roche total Ig) and Architect SARS-CoV-2 IgG (Abbott IgG) (Table 2). We considered a 1.0 COI or more titers of the Roche total Ig and 1.4 index (S/C) or more of the Abbott IgG as positive results. The Roche Elecsys ® Anti SARS-CoV-2 (“Elecsys” in short form) assay, our reference assasy, uses a recombinant protein representing the nucleocapsid (N) antigen for the determination of IgG The day before infection, VeroE6 cells were seeded at 12,500 cells/well into 96-well plates. Antibodies were serially diluted in BA-1, mixed with a constant amount of SARS-CoV-2 (grown in VeroE6 PMC8306884. 10.3390/diagnostics11071135. (1) Background: The evaluation of anti-spike protein receptor-binding domain (S-RBD) antibodies represents a useful tool to estimate the individual protection against Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) infection; (2) Methods: We evaluated anti S-RBD IgG levels by indirect After SARS -CoV-2 infection, anti -SARS-CoV-2 antibodies will appear in the blood of human body resulting from adaptive immune response in most individuals. Usually IgM antibodies can be SARS-CoV-2 RNA was detected in 161 participants (4.7%): 113 of 827 were symptomatic (13.7%) and 48 of 2592 were asymptomatic (1.9%). In symptomatic participants presenting within 7 days of symptom onset, the sensitivity and specificity of the BinaxNOW device were 71.1% and 100%, respectively. Background:Limited information is currently available regarding the global incidence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections prior to the declaration of the coronavirus disease 2019 (COVID-19) pandemic, which may result in improper conclusions regarding the timing of viral transmission.MethodsWe investigated the presence of specific antibodies against the aRDHl9.