Most of the cases were relatively mild as only CRP C-reactive protein, RV rhinovirus, SD standard deviation, SpO 2 peripheral oxygen saturation a 38.0°C or more any time during the illness (before or upon enrolment, or during follow-up) b 39.0°C or more any time during the illness (before or upon enrolment, or during follow-up) *p<0.05 vs RV-C.