Performance of the COVID-19 SEROSpeed IgM/IgG Rapid Test, an immunochromatographic assay for the diagnosis of SARS-CoV-2 infection: a multicenter European study.

This study assessed the diagnostic performance of the new COVID-19 SEROSpeed IgM/IgG Rapid Test (BioSpeedia, spin-off of the Pasteur Institute of Paris) for the detection of antibodies against SARS-CoV-2 in comparison to other commercial antibody assays through a large cross-European study. The clinical specificity was assessed on 215 pre-pandemic sera (including some from patients with viral infections or autoimmune disorders). The clinical sensitivity was evaluated on 710 sera from 564 patients whose SARS-CoV-2 infection was confirmed by qRT-PCR and whose antibody response was compared to that measured by five other commercial tests. The kinetics of the antibody response were also analyzed in seven symptomatic patients. The specificity of the test (BioS) on pre-pandemic specimens was 98.1% (95% CI: 96.2-99.4). When tested on the 710 pandemic specimens, BioS showed an overall clinical sensitivity of 86.0% (95% CI: 0.83-0.89), with good concordance with the Euroimmun assay (overall concordance of 0.91; Cohen's kappa coefficient of 0.62). Due in part to simultaneous detection of IgM and IgG for both S1 and N proteins, BioS exhibited the highest positive percent agreement ≥11 days post symptom onset (PSO). In conclusion, the BioS IgM/IgG rapid test was highly specific and demonstrated higher positive percent agreement compared to all the ELISA/CLIA commercial tests considered in this study. Moreover, by detecting the presence of antibodies prior to 11 days PSO in 78.2% of the patients, the BioS test increased the efficiency of the diagnosis of SARS-CoV-2 infection in the early stages of the disease.