Clinical features, efficacy, and safety of antiviral drugs in children with influenza A and B: A retrospective cohort study

Background : Studies comparing the efficacy and safety of different antiviral drugs for pediatric influenza remain limited. This study aimed to compare the clinical features of influenza A and B in children and evaluate the safety and efficacy of oseltamivir, baloxavir marboxil, and peramivir to optimize antiviral treatment strategies for pediatric influenza. Methods : This retrospective cohort study included 3,718 pediatric patients diagnosed with influenza A or B between November 2023 and April 2024. The patients were divided into influenza A and B groups and further categorized according to the antiviral medications they received. Patient information, clinical manifestations, laboratory findings, and treatment data were collected. Propensity score matching was applied to control for confounding factors. Linear regression analysis was performed to explore factors influencing disease outcomes. Results : Children with influenza A had significantly higher fever peaks and more frequent fever episodes than those with influenza B and were more likely to experience cough, rhinorrhea, and neurological complications. Contrastingly, children with influenza B exhibited more pronounced gastrointestinal symptoms such as nausea and vomiting. Both the baloxavir marboxil and peramivir groups had significantly shorter fever resolution times than the oseltamivir group; among influenza B patients, the baloxavir marboxil group had a shorter fever resolution time than the peramivir group. In terms of recovery time, the peramivir group outperformed the oseltamivir group. Safety analysis revealed the highest incidence of adverse events in the oseltamivir group (16.5%), followed by the peramivir (5.0%) and baloxavir marboxil groups (3.6%). All adverse events were mild to moderate; no severe adverse events were reported. Linear regression analysis indicated that different treatment regimens and the presence of pneumonia significantly affected fever resolution time and that both fever resolution time and pneumonia were key factors influencing recovery time. Conclusions : The clinical presentation and complications differed between children with influenza A and B. Baloxavir marboxil and peramivir demonstrated superior efficacy and safety compared with oseltamivir, and the single-dose oral regimen of baloxavir marboxil significantly improved treatment adherence. Meanwhile, peramivir exhibited advantages in the treatment of severe cases. These results will aid in clinical decision making and optimizing antiviral treatment strategies for pediatric influenza.