This is an exploratory prospective study (a study in which the patients are identified and then followed forward in time for the outcome of the study). The study will consist of two phases: a screening phase (Day 1) and an assessment phase (Day 2 to Day 7). During screening phase, in pediatric patients hospitalized with LRTI and from whom the informed consent form was obtained, diagnosis of RSV infection will be performed within 24h from the hospital admission, using a SOFIA POC test on nasal specimens. During the assessment phase the collection of nasal specimens will be done daily for a maximum of 6 days (Day 2 to Day 7 of hospitalization) or until patient discharge from hospital. Approximately 50 patients will be enrolled in this study. The total duration of the study for each participant will be approximately 7 days. The study duration will extend during 1-3 RSV epidemic seasons, or until the targeted number of 50 RSV hospitalized children have completed the study.