The study is planned to evaluate the therapeutic efficacy and safety of Ingavirin®, capsules, 60 mg, in the treatment of influenza or other acute respiratory infections in children from 13 to 17 years compared with placebo.

Inclusion Criteria:

1. Male and female patients aged 13 to 17 years inclusive.
2. Clinically established diagnosis of influenza or acute respiratory viral infection based on the presence of body temperature > 37.5 °C and at least 1 of the following symptoms of intoxication syndrome, and at least 1 manifestation of catarrhal syndrome: symptoms of intoxication syndrome (headache, chills, weakness, brokenness, eyeball pain, nausea); catarrhal syndrome (sore throat, rhinitis, pharyngitis, laryngitis, cough).
3. Laboratory-confirmed diagnosis of influenza or acute respiratory viral infections using one or more of the following viral antigen detection methods.
4. Uncomplicated course of influenza or ARVI.
5. Interval between the onset of the first symptoms of the disease and inclusion in the study no more than 36 h.
6. Availability of an informed consent form signed by one of the parents (or legal representatives) of the child for participation in the study.
7. For patients 14 years and older, a signed informed consent form for participation in the study.

Exclusion Criteria:

1. Hypersensitivity to any of the components included in the Ingavirin®.
2. Complicated course of influenza and acute respiratory viral infections (clinically and laboratory determined bacterial infection).
3. Taking antiviral drugs (antiviral agents, interferons, interferon inducers and drugs with immunomodulatory effect) or systemic antibacterial agents 7 days prior to the Screening Visit.
4. Severe influenza with signs of cardiovascular failure and other manifestations of infectious-toxic shock, as well as with the presence of neuroinfection syndrome (encephalic and meningoencephalic reactions).
5. Signs of viral pneumonia (presence of two or more of the following symptoms: dyspnea, chest pain when coughing, systemic cyanosis, dulling of the percussion sound with symmetric evaluation of the upper and lower lungs).
6. Infectious diseases suffered during the last week before inclusion of the patient in the study.
7. "Frequently ill children" (frequency of acute respiratory illnesses during the last year 6 times or more).
8. A history of bronchial asthma.
9. A history of increased seizure activity.
10. Severe, decompensated or unstable somatic diseases (any diseases or conditions that threaten the patient's life or worsen the patient's prognosis, as well as make it impossible to conduct a clinical trial in the patient).
11. History of oncologic diseases, HIV infection, tuberculosis.
12. Diabetes mellitus, lactose intolerance, lactase deficiency, glucose-galactose malabsorption, sucrose/isomaltase deficiency, fructose intolerance, hereditary disorders of glucose absorption, glucose-6-phosphate dehydrogenase deficiency.
13. Participation in a clinical drug trial less than 3 months prior to the start of the study.
14. Immunization of the patient 14 days prior to the Screening Visit.
15. The need for concomitant therapy with any of the drugs listed under "Prohibited Concomitant Treatment".
16. Any other concomitant somatic diseases or conditions that, in the opinion of the investigator, make it difficult to interpret the results of treatment or result in the inability to perform the procedures in this clinical trial or pose a risk to the patient in participating in the study.
17. For female patients, a positive urine pregnancy test if menstrual cycle is present.