this study evaluates the use of Kagocel for the prevention of acute respiratory viral infections (ARVI) and influenza during the epidemic rise in morbidity in Russia in the 2017-2018 season (epidemiology: number of cases during the period of taking Kagocel and follow-up, severity of the disease, bacterial exacerbations, number of repeated episodes (reinfection); patients demography; safety) in health care workers who are at risk.

This non-interventional prospective study included 204 health care workers over the age of 18 who had no symptoms of acute respiratory viral infections (ARVI) and influenza at the time of inclusion and had not taken any antiviral medications to prevent ARVI and influenza for 30 days before.

The total duration of the study was 2 months: the first month participants took either Kagocel (the main group), or did not take anything at all (the control group), during the next 1 month all participants were monitored.

The diagnosis of influenza and ARVI has been confirmed in accordance with the world health organization (WHO) guidelines for the pharmacological treatment of pandemic influenza A (H1N1) 2009 and other influenza viruses. All patient examinations are conducted in accordance with local routine clinical practice and local and international standards of care.

By the study were analysed and compared those data between groups:

• demography
• anamnesis data (the incidence of ARVI and flu, the date of the lastest episode of the disease, the presence of concomitant diseases, including ENT-organs, the date of the lastest influenza vaccination).
• timelines: start of Kagocel's prevention - only for the group receiving Kagocel's prevention, start of the disease, duration of ARVI and influenza symptoms (fever, headache, runny nose, sore throat, cough), start of treatment
• need for antiviral therapy (Yes/no)
• antiviral therapy (Yes/no, drug name)
• bacterial exacerbations (Yes/no)
• treatment of bacterial exacerbations (Yes/no)
• adverse events

Inclusion Criteria:

• signed informed consent to participate in the study.
• age from 18 to 70 years.
• the subject of the study does not have symptoms of ARVI and influenza at the time of inclusion in the study.
• there are no contraindications to the use of Kagocel: pregnancy and lactation, hypersensitivity to the components of the drug, lactase deficiency, lactose intolerance, glucose-galactose malabsorption (only for the group receiving kagocel prevention).
• the subject of the study should not to take other medications to prevent colds and flu while participating in the study.
• no history of participation in a clinical trial of any drug less than 30 days prior to inclusion in this study.
• no history of treatment by interferon or interferon inducers less than 30 days prior to inclusion in this study.

Exclusion Criteria:

• no exclusion criteria except participating in a current clinical trial because of non-interventional study design

health care workers over the age of 18 who had no symptoms of acute respiratory viral infections (ARVI) and influenza at the time of inclusion and had not taken any antiviral medications to prevent ARVI and influenza than 30 days prior to inclusion in this study.