Clinical specimens shall be collected prospectively from patients with signs or symptoms of respiratory tract infection. Nasal swab in Copan universal transport media (UTM) 3 milliliters for comparator testing should be collected by a healthcare professional.

Where subjects are willing and able, up to 40% of nasal swab for the investigational device will be self-collected under the guidance and supervision of a healthcare professional.

Nasopharyngeal (NPS) specimens (optional) should only be collected by a healthcare professional. All specimens collected from children 13 years or younger should only be collected by a trained healthcare professional. Follow the Centers for Disease Control and Prevention guidelines for collecting NPS swabs, unless otherwise specified by the sponsor.

The LIAISON® NES FLU A/B & COVID-19 assay used on the LIAISON® NES instrument is a real-time PCR system that enables the direct amplification, detection and differentiation of Flu A viral RNA, Flu B viral RNA and SARS-CoV-2 RNA from dry nasal swabs. Nasal Swabs can be professionally collected by a Healthcare Provider or self-collected by the patient under the supervision of the healthcare provider. The collected nasal swab can then be directly loaded into the cartridge without nucleic acid extraction.

Estimates of Sensitivity/percent positive agreement (PPA) and Specificity/percent negative agreement (NPA) will be calculated based on a two-by-two table (comparator method result vs. result from LIAISON® NES FLU A/B, RSV & COVID-19 assay or LIAISON PLEX® RSP Flex assay) for each target. In addition, 95% two-sided confidence intervals will be provided. A separate Sensitivity/PPA and Specificity/NPA for each target, to include those specimens excluded due to a discrepancy between the standard-of-care and molecular comparator result, will be presented in a separate 2 x 2 table.