CRP and susceptibility to pneumonia measurement: In the study [59,62], COVID-19 pediatric patients had lower severity of illness (clinical profile and outcomes) than children with influenza: lymphocyte count and D-dimer were lower in influenza A patients than in COVID-19, and the severity index of pneumonia (CRP, PCT (procalcitonin)) was lower in COVID-19 than influenza A. Ground-glass opacity was more common in COVID-19 patients than in influenza A patients, and consolidation was more frequent in influenza A patients [62].