The mechanism how miRNA affect the process of virus infection in mutated SARS-CoV-2 infection. In virus-free status, miR-570-5p binding to the 3'-UTR of COX-2 mRNA leads to COX-2 normal expression and homeostatic balance in host cells; during SARS-CoV-2 infection, the virus releases its genome in host cells to captain intracellular miR-570-5p, which results in the decrease of the miRNA in COX-2 mRNA 3'-UTR and triggers to COX-2 accumulation-induced inflammatory response in lungs; during mutated SARS-CoV-2 (Gene: 23,403 A > G) infection, due to the stronger interactions between viral genome and miR-570-5p, it is followingly reduction of interactions, excessive COX-2 accumulation and enhance of inflammatory response in lungs which may cause more severe symptoms in patients.