The availability of a detailed evaluation of COVID-19 symptoms, relative severity assessment, and TAS2R38 and TAS1R2/3 genetic analyses allowed us to (1) clarify the role of TAS2R38 in determining COVID-19 symptom severity, (2) investigate, for the first time, the role of TAS1Rs in the immune response to viral infections. This evidence concerns the gene TAS2R38 and viral infectious disease.