Children had less severe illness from COVID-19 than expected, and initial research on this phenomenon showed that children have heightened non-specific (“innate”) nasal immune responses compared to adults.
Common cold infections can block more pathogenic viruses through effects on innate immunity
Epithelial cells show tradeoff between antioxidant and antiviral defense.
While standard diagnostic tests for viruses (e.g. PCR) are virus-specific, but the body's innate immune sensors can diagnose broad categories of infection with no prior knowledge of the pathogen.