Multicenter double-blind placebo-controlled randomized in parallel groups clinical trial.
Children of either gender aged 3 to12 years .
Diagnosis of ARVI based on the medical examination: axillary temperature ≥37.8°C at the time of examination + total severity of general symptom score ≥4 points, nasal/throat/chest symptoms ≥2 points (ARVI Symptom Severity Score).
24 hours from the ARVI onset .
Availability of a patient information sheet and an informed consent form for the patient's parents/adopters for patient participation in the clinical trial signed by one parent/adopter of the patient.
Clinical symptoms of severe influenza/ARVI requiring hospitalization.
Suspected pneumonia, bacterial infection (including otitis media, sinusitis, urinary tract infection, meningitis, sepsis, etc.) requiring the administration of antibiotics from the first day of disease.
Suspected early manifestations of diseases that have onset symptoms similar to those of ARVI (other infectious diseases, influenza-like syndrome at the onset of systemic connective tissue diseases and other pathologies).
Patients who require administration of antiviral medications that are prohibited for use in this trial.