Acute Severity Versus Long-term Morbidity: Uncoupling the Roles of RSV and HRV in Childhood Respiratory Disease.

Background: The distinct roles of respiratory syncytial virus (RSV) and human rhinovirus (HRV) in acute illness and subsequent asthma remain debated. China's strict nonpharmaceutical interventions (NPIs) in 2022 provided a unique epidemiological setting to compare their clinical/inflammatory profiles and associations with long-term asthma risk. Methods: This observational retrospective cohort study included children hospitalized with RSV- or HRV-induced acute lower respiratory tract infections. We collected clinical data, subtyped RSV samples and conducted long-term follow-up to assess physician-diagnosed asthma using Kaplan-Meier and multivariable logistic regression. Results: Among 722 children (425 RSV, 275 HRV, and 22 coinfection), RSV predominated in infants with a sharp winter peak (RSV-A dominant, 96.8%), while HRV circulated year-round across a broader age range. RSV infection was associated with greater acute severity, including higher rates of pneumonia and longer hospitalization ( Conclusions: During China's late NPI phase, HRV infection showed a stronger independent association with childhood asthma than RSV. This association, together with an eosinophil-predominant inflammatory profile, remained significant after adjustment for prior wheezing history. These findings should be interpreted as associations rather than evidence of causality.