Performance evaluation of the BD SARS-CoV-2 reagents for the BD MAX™ system (preprint)

BackgroundThe RT-qPCR assay for detecting SARS-CoV-2 virus is the favorable approach to test suspected COVID-19 cases. However, discordant results can occur when two or more assays are compared. Variability in analytical sensitivities between assays, among other factors, may account for these differences in reporting. MethodsThe limits of detection (LOD) for the BD SARS-CoV-2 Reagents for BD MAX System ("MAX SARS-CoV-2 assay"), the Biomerieux BioFire(R) Respiratory Panel 2.1 ("BioFire SARS-CoV-2 assay"), the Roche cobas SARS-CoV-2 assay ("cobas SARS-CoV-2 assay"), and the Hologic Aptima(R) SARS-CoV-2 assay Panther(R) ("Aptima SARS-CoV-2 assay") RT-qPCR systems were determined using a total of 84 contrived nasopharyngeal specimens with seven target levels for each comparator. The positive and negative percent agreement (PPA and NPA, respectively) for the MAX SARS-CoV-2 assay were compared to the Aptima SARS-CoV-2 assay in a post-market clinical study utilizing 708 paired nasopharyngeal specimens collected from suspected COVID-19 cases. Discordant results were further tested by the cobas and BioFire SARS-CoV-2 assays. ResultsThe measured LOD for the MAX SARS-CoV-2 assay (251 copies/mL) was comparable to the cobas SARS-CoV-2 assay (298 copies/mL) and the BioFire SARS-CoV-2 assay (302 copies/mL); the Aptima SARS-CoV-2 assay had a LOD of 612 copies/mL. The MAX SARS-CoV-2 assay had a PPA of 100% (95%CI: [97.3%-100.0%]) and a NPA of 96.7% (95%CI: [94.9%-97.9%]) when compared to the Aptima SARS-CoV-2 assay. ConclusionsThe MAX SARS-CoV-2 assay exhibited a high analytical sensitivity and specificity for SARS-CoV-2 detection. The clinical performance of the MAX SARS-CoV-2 assay agreed with another sensitive EUA cleared assay.

Clinical evaluation of the molecular-based BD SARS-CoV-2/Flu for the BD MAX™ System (preprint)

Efficient and accurate assays for the differential diagnosis of COVID-19 and/or influenza (flu) could facilitate optimal treatment for both diseases. Diagnostic performance related to SARS-CoV-2 and Flu A/B detection was characterized for the BD SARS-CoV-2/Flu for BD MAX System (MAX SARS-CoV-2/Flu) multiplex assay in comparison with BD BioGx SARS-CoV-2 Reagents for BD MAX System (BioGx SARS-CoV-2) and the Cepheid Xpert(R) Xpress Flu/RSV (Xpert Flu). Two hundred and thirty-five nasopharyngeal specimens were obtained from external vendors. MAX SARS-CoV-2/Flu had positive percent agreement (PPA) and negative percent agreement (NPA) values for SARS-CoV-2 and Flu A/B that met FDA-EUA acceptance criteria of >95%.