COVID-19(26) SARS-CoV-2(15) severity(7) Patient(7) coronavirus(6) association(6) Mortality(6) analysis(5) Mild(5) Comorbidity(5) performed(5) death rate(4) Intracellular(4) Mitochondria(4) maintain(4) Protein(4) patients(4) Intracellular temperature(4) Clinical data(4) healthy(4) spike protein.(4) mitochondrial dysfunction(4) Evidence(4) Mitochondrial Disease(4) attribute(4) aggravate(4) temperature(4) fatality(4) mitochondrial(4) Severity of infection(4)