Humoral Immune Response to SARS-CoV-2

Area of Science:

• Immunology
• Infectious Diseases
• Diagnostic Assay Development

Background:

• Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) serology tests are vital for confirming past infections.
• There is an urgent need for data to guide the selection of highly sensitive and specific antibody detection assays.

Purpose of the Study:

• To comparatively evaluate the performance of seven commercial SARS-CoV-2 serology assays.
• To assess sensitivity, specificity, and kinetics of antibody detection.

Main Methods:

• Evaluation of 7 commercial SARS-CoV-2 serology assays using 171 sera from 135 PCR-confirmed SARS-CoV-2 infected individuals.
• Analysis of IgA/IgM/IgG seroconversion kinetics to N and S protein epitopes from 0 to 54 days post-symptom onset.
• Verification of cross-reactivity using 57 pre-pandemic samples.

Main Results:

• Wantai SARS-COV-2 Ab ELISA and Orient Gene COVID-19 IgG/IgM Rapid Test showed superior overall sensitivity.
• Elecsys Anti-SARS-CoV-2 and EUROIMMUN Anti-SARS-CoV-2 demonstrated >95% sensitivity from 10 days post-symptom onset.
• Wantai SARS-COV-2 Ab ELISA, Elecsys Anti-SARS-CoV-2, and Innovita 2019-nCoV Ab rapid test exhibited optimal analytical specificity (>98%) with minimal cross-reactivity.

Conclusions:

• Wantai SARS-COV-2 Ab ELISA and Elecsys Anti-SARS-CoV-2 assays are suitable for sensitive and specific detection of SARS-CoV-2 antibodies.
• These assays are recommended for use from 10 days after symptom onset for reliable detection of prior SARS-CoV-2 infection.