An adjusted ELISpot-based immunoassay for evaluation of SARS-CoV-2-specific T-cell responses

•Scientific question: This study proposed and evaluated a modified SARS-CoV-2-specific immunoassay with high validity.•Evidence before this study: The number of confirmed COVID-19 cases is increasing globally. Compared with humoral immunity, the evaluation of SARS-CoV-2-specific cellular immunity has not been completely unified and standardized, and has the characteristics of complex operation and high requirements of equipment.•New findings: An assessment of the SARS-CoV-2-specific T-cell responses of COVID-19 convalescents and healthy individuals was conducted through an adjusted ELISpot-based immunoassay in this study. The data showed that the parallel combination test and serial combination test of SARS-CoV-2 peptide pools showed higher sensitivity and specificity, respectively. The combined detection of peptide pools could obtain higher detection efficiency, especially the serial test, whose Youden indices were generally better than that of the parallel test. Combination of M and N peptide pool serial evaluation is optimal.•Significance of the study: The SARS-CoV-2-specific T-cell immunoassay proposed in this study is practical and valid, which is conducive to promote the standardized assessment of immune responses to SARS-CoV-2 variants, vaccines and diagnosis.