IFNA17 and COVID-19: We thus implemented a targeted metabolomics approach based on liquid chromatography tandem mass spectrometry (LC–MS/MS) to (1) characterize small-molecule profiles in viral transport media (VTM) from NP swabs of patients infected with INFA, RSV or COVID-19 and unaffected controls; (2) identify COVID-19 specific metabolite patterns; and (3) explore potential therapeutic pathways based on significant metabolites identified by a supervised machine learning model (Fig. 1).