Ultrasensitive monitoring of SARS-CoV-2-specific antibody responses based on a digital approach reveals one week of IgG seroconversion

SARS-CoV-2 peptides/epitopes for specific and sensitive diagnosis

“…Compared to full-length protein antigen or antigen domain-based detection, there are several advantages of peptide/epitope-based detection. For example, peptide/epitope based detection methods have higher stability and lower cost, and they can be scaled up easily by chemical synthesis in a very short time [ 3 ].…”

“…Despite the advantages of epitopes [ 1 ], they also have limitations. For example, peptides/epitopes have much lower mass and surface accessibility than full-length proteins [ 3 ]. This makes it challenging to achieve performance as high as that of traditional ELISA or flow cytometry assays, resulting in limited applications of peptides in clinical practice.…”

“…Among the peptides tested, the p2pS mimotope exhibited optimal performance, achieving excellent sensitivity and specificity. Ou et al developed an optimized ultrasensitive assay called UIM-COVID-19, which combined the single-molecule array platform (Simoa), receptor binding domain (RBD), and peptide S2-78 [ 1 , 3 ]. The UIM-COVID-19 assay showed excellent differentiation ability between COVID-19 patients (convalescents) and healthy individuals or patients with other diseases, with AUC values ranging from 0.85 to 0.95.…”