The trial will be conducted in three stages.~• Stage I Participants - children aged 10 to 17 years (10 years 0 months 0 days - 17 years 11 months 30 days), will be vaccinated a single 0.5 mL dose of the Flu-M Tetra vaccine or the VaxigripTetra vaccine intramuscularly.~Once reviewed by the Sponsor, the report will be submitted to the supervisory executive authorities alongside the notice of commencement of Stage II trial.~• Stage II Participants - children aged 3 to 9 years (3 years 0 months 0 days - 9 years 11 months 30 days), will be vaccinated a single 0.5 mL dose of the Flu-M Tetra vaccine or the VaxigripTetra vaccine intramuscularly (double dose for volunteers who have not been vaccinated before).~Once reviewed by the Sponsor, the report will be submitted to the supervisory executive authorities alongside the notice of commencement of Stage III trial.~• Stage III Participants - children aged 6 to 35 months (6 months 0 days - 35 months 30 days), will be vaccinated twice 0.25 mL dose of the Flu-M Tetra vaccine or the VaxigripTetra vaccine intramuscularly.
The goal of this clinical trial is to assess tolerability, reactogenicity, safety and immunogenicity of the Flu-M Tetra vaccine as compared to the VaxigripTetra vaccine in terms of prevention of influenza in children aged 6 months to 17 years old inclusive.