Background: COVID-19 and influenza (flu) share similar clinical symptoms. Therefore, differential detection of these viruses during the respiratory virus season will be an important component for proper patient triage, management, and treatment. Objectives: Establish the diagnostic performance related to SARS-CoV-2 and Flu A/B detection for the BD SARSCoV-2/Flu for BD MAXTM System ("MAX SARS-CoV-2/Flu") multiplex assay. Materials and methods: Two hundred and thirty-five (235) retrospective nasopharyngeal specimens were obtained from external vendors. The BD BioGx SARS-CoV-2 Reagents for BD MAXTM System ("BioGx SARS-CoV-2 '') and the Cepheid Xpert (R) Xpress Flu/RSV ("Xpert Flu/RSV") were utilized as reference methods. Results: By reference methods, 52 specimens were SARS-CoV-2-positive, 59 were Flu A-positive, and 60 were Flu B-positive. MAX SARS-CoV-2/Flu had positive percent agreement (PPA) and negative percent agreement (NPA) values for SARS-CoV-2 detection of 96.2% ([95%CI]:87.0-98.9) and 100% [95%CI:88.7-100], respectively; PPA values for Flu A and Flu B of 100% [95%CI:93.9-100] and 98.3% [95%CI:91.1-99.7], respectively, and NPA values for Flu A and Flu B of 98.9% [95%CI:94.0-99.8] and 100% [95%CI:95.9-100], respectively. Conclusions: The MAX SARS-CoV-2/Flu assay met FDA-EUA performance criteria for SARS-CoV-2 (>95% for PPA and NPA) and FDA clearance criteria for Flu A/B (PPA >90%; lower bound of the 95%CI >80% and NPA >95%; lower bound of the 95%CI >90%).
