This is a multicenter, randomized, open-label, parallel-controlled, prospective clinical study. It aims to evaluate the efficacy and safety of aerosolized Peginterferon α-2b injection in the treatment of pediatric respiratory syncytial virus pneumonia. The overall study is divided into a screening period, a treatment period, and a follow-up period. Eligible children with respiratory syncytial virus pneumonia will be randomly assigned to the experimental group 1, experimental group 2, and the control group at a ratio of 1:1:1.

Inclusion Criteria:

• (1)Age: 1 year ≤ age ≤ 3 years; (2) Gender: Both male and female participants are eligible; (3) According to the 9th edition of "Zhu Fute's Practical Pediatrics," meet the following diagnostic criteria: a. RSV test positive; b. Clinical manifestations: Fever, cough, wheezing; c. Physical signs: Rapid breathing and moist rales in the lungs; (4) Time: The time from the onset of the child's illness to the signing of the informed consent form is within 72 hours (starting from the occurrence of any symptom such as fever, cough, or wheezing); (5) Informed consent: The legal guardian of the child understands and signs the informed consent form (if the legal guardians are the parents, both parents need to sign together).

Exclusion Criteria:

• (1) Presence of any of the following clinical symptoms before enrollment: a. Poor general condition, with altered consciousness, refusal to eat, or signs of dehydration; b. Hypoxemia: Presence of cyanosis, rapid breathing (RR ≥ 50 breaths per minute), stridor, nasal flaring, tracheal tug, oxygen saturation < 92%, and intermittent apnea; c. Extrapulmonary complications; d. Chest X-ray or CT: Multilobar lung infiltrates, pleural effusion, pneumothorax, atelectasis, lung necrosis, and lung abscess; e. Hyperpyrexia: Persistent high fever for more than 5 days; f. Presence of critical complications such as respiratory failure and circulatory failure; (2) Allergy history and treatment history: a. Receiving antiviral drug treatment with interferon, ribavirin, acyclovir, ganciclovir, or vidarabine monophosphate within 30 days before screening or currently; b. Receiving immunoglobulin treatment within 30 days before screening or currently; c. Known hypersensitivity to interferon or its components, or a clear history of other allergies that make participation in this study inappropriate; d. Use of other investigational drugs within 3 months before screening or within 5 half-lives (whichever is longer), or currently participating in a clinical trial for a medical device at the time of screening; (3) Disease history and current medical history: a. History of congenital heart disease, severe malnutrition, abnormal immune system function, or other serious diseases of major organ systems; b. Severe liver or renal dysfunction; c. History of viral infections such as HBV, HCV, HIV; d. Past or current history of malignant tumors; e. Past history of epilepsy, or history and family history of neurological/psychiatric disorders; (4) Other conditions: Subjects deemed unsuitable for participation in this trial by the investigator.