Background SARS‐CoV‐2 pandemic is currently ongoing, meanwhile vaccinations are rapidly underway in some countries. The quantitative immunoassays detecting antibodies against spike antigen of SARS‐CoV‐2 have been developed based on the findings that they have a better correlation with the neutralizing antibody. Methods The performances of the Abbott Architect SARS‐CoV‐2 IgG II Quant, DiaSorin LIAISON SARS‐CoV‐2 TrimericS IgG, and Roche Elecsys anti‐SARS‐CoV‐2 S were evaluated on 173 sera from 126 SARS‐CoV‐2 patients and 151 pre‐pandemic sera. Their correlations with GenScript cPass SARS‐CoV‐2 Neutralization Antibody Detection Kit were also analyzed on 173 sera from 126 SARS‐CoV‐2 patients. Results Architect SARS‐CoV‐2 IgG II Quant and Elecsys anti‐SARS‐CoV‐2 S showed the highest overall sensitivity (96.0%), followed by LIAISON SARS‐CoV‐2 TrimericS IgG (93.6%). The specificities of Elecsys anti‐SARS‐CoV‐2 S and LIAISON SARS‐CoV‐2 TrimericS IgG were 100.0%, followed by Architect SARS‐CoV‐2 IgG II Quant (99.3%). Regarding the correlation with cPass neutralization antibody assay, LIAISON SARS‐CoV‐2 TrimericS IgG showed the best correlation (Spearman rho = 0.88), followed by Architect SARS‐CoV‐2 IgG II Quant and Elecsys anti‐SARS‐CoV‐2 S (all rho = 0.87). Conclusions The three automated quantitative immunoassays showed good diagnostic performance and strong correlations with neutralization antibodies. These assays will be useful in diagnostic assistance, evaluating the response to vaccination, and the assessment of herd immunity in the future.

RHD genotyping is not required in half of D-negative cases. We suggest here an effective RHD genotyping strategy for accurate detection of RhD variants in apparently RhD-negative blood donors in East Asia.

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It is often difficult for standard blood banks in Korea to supply adequate amounts of blood for patients with rare phenotype. Moreover, the definition of a blood in need is ambiguous, and much remains to be learned. In this study, we determined the prevalence of various red blood cell (RBC) antigens from a donor viewpoint and estimated the demand for specific antigen-negative blood from a patient viewpoint. Our data will aid the establishment of a Rare Blood Program in Korea (KRBP). RBC genotyping of 419 blood donors was performed using a Lifecodes RBC/RBC-R typing kit (Immucor, Norcross, GA). A national recipient registry website has been established. Each hospital-based blood bank voluntarily enters data on antibodies detected and identified and the outcomes of specific antigen testing. We calculated the availabilities of specific antigen-negative blood components based on these registry data and predicted the prevalence of RBC antigens via RBC genotyping. The prevalences of various RBC antigens in the D-negative population were determined for the first time, and the Cartwright, Scianna, Dombrock, Colton, Landsteiner-Wiener, Cromer, and Knops blood group systems were identified. The availabilities of specific antigen-negative units differed when calculations were based on serotyping or genotyping, especially in the D-negative group. Data on the prevalences of various blood antigens are essential for estimating the availabilities of blood components that are appropriate for use by patients expressing relevant antibodies. Then, blood banks would be able to efficiently supply safe blood products.