Evaluation of the STANDARD M10 Flu/RSV/SARS-CoV-2 Fast assay for the detection of influenza A/B viruses, respiratory syncytial virus, and SARS-CoV-2 in nasopharyngeal swab specimens

The STANDARD M10 Flu/RSV/SARS-CoV-2 Fast assay (M10 Fast), recently CE-marked, is an updated version of the STANDARD M10 Flu/RSV/SARS-CoV-2 assay. It includes additional gene targets to improve sensitivity and coverage and reduces run time from 60 min to 36 min. This study evaluated the analytical and clinical performance of the M10 Fast assay. A total of 664 nasopharyngeal swab specimens (108 influenza A-positive, 119 influenza B-positive, 79 respiratory syncytial virus [RSV]-positive, 165 SARS-CoV-2-positive, 2 influenza A/RSV co-positive, 1 RSV/SARS-CoV-2 co-positive, and 190 negative), confirmed by the BIOFIRE Respiratory Panel 2.1 <i>plus</i> (RP2.1<i>plus</i>), were tested in parallel using the M10 Fast assay and the Allplex SARS-CoV-2/FluA/FluB/RSV assay (Allplex). RNA standards were serially diluted and tested with the M10 Fast assay to determine the limit of detection (LOD). Using RP2.1<i>plus</i> as the reference standard, the M10 Fast assay demonstrated sensitivities of 98.2%, 100%, 95.1%, and 100% for influenza A, influenza B, RSV, and SARS-CoV-2, respectively. The Allplex assay showed sensitivities of 88.2%, 100%, 91.5%, and 100% for the same viruses. Both assays exhibited high specificity (>99%). The LODs of the M10 Fast assay were 7.8, 35.3, 532.7, 34.7, and 88.0 copies/mL for influenza A, influenza B, RSV, and SARS-CoV-2 ORF1ab/E and N genes, respectively, and were lower than previously reported Allplex LODs, except for RSV. The M10 Fast assay reliably detects influenza A and B, RSV, and SARS-CoV-2 with high sensitivity and specificity, demonstrating performance comparable to or exceeding that of the widely used Allplex assay.IMPORTANCEThe STANDARD M10 Flu/RSV/SARS-CoV-2 Fast assay (M10 Fast) is an updated version of the STANDARD M10 Flu/RSV/SARS-CoV-2 assay. This study demonstrates that the M10 Fast assay reliably detects influenza A and B, respiratory syncytial virus (RSV), and SARS-CoV-2 with high sensitivity and specificity, including improved detection at low viral loads. Its enhanced performance and shorter turnaround time support timely clinical decision-making and strengthen public health responses, particularly during periods of cocirculation of influenza, RSV, and SARS-CoV-2.