Study to Assess the Tolerability, Safety and Efficacy of GP681 Powder for Oral Suspension

This study aims to evaluate the tolerability, safety, pharmacokinetic characteristics and efficacy of a single oral dose of GP681 powder for oral suspension in pediatric and adolescent patients with uncomplicated influenza. The study will also explore the optimal dose for a confirmatory clinical trial. Eligible patients who have been confirmed influenza virus infection and have experienced influenza symptoms within 48 hours prior to enrollment, will receive single dose of GP681 powder for oral suspension. The primary outcome measures included the observation of adverse events during the study, the pharmacokinetic parameters, as well as the efficacy endpoints including time to alleviation of influenza symptoms, viral clearance rate, changes in viral load, etc.