Mild SARS-CoV-2 infections in children might be based on evolutionary biology and linked with host reactive oxidative stress and antioxidant capabilities

Severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) infection leads to significant morbidity and mortality in elderly. Children typically have mild illness with rare mortalities. Age and comorbid medical conditions are the most important determinant of the infection outcome. Currently there is no clear explanation for difference in disease severity and outcome in different age groups. Based on evolutionary biology and translational research this review suggests that high antioxidant capacity of children leading to a balanced redox state is the key factor for mild SARS-COV-2 infections in this age group. On the other hand, elderly with low antioxidant capacity and ACE2 expression is prone to severe infections by redox sensitive immune modulation.