Several host factors, including C-reactive protein (CRP), procalcitonin (PCT), mid-regional proadrenomedullin (MR-proADM), presepsin, ferritin, kynurenine, miRNAs, and host gene signatures, have demonstrated potential in differentiating viral infections from other conditions and predict disease outcomes [1,2,3,4,5,6,7,8,9,10]. Here, CRP is linked to viral infectious disease.