This trial by its design was a prospective, multicenter, double blind, randomized comparative clinical trial of the IIIb-IV phase which was carried out in parallel groups of volunteers over the age of 60

The volunteers will include in the trial will divide into two groups:

Group 1: volunteers who will receive one dose of Flu-M, solution for intramuscular injection, 0.5 mL, intramuscularly.

Group 2: volunteers who will receive one dose of Ultrix®, solution for intramuscular administration, 0.5 mL, intramuscularly.

The trial include the following periods and visits:

1. Screening period (up to 7 days):

   • Visit 0 (day -7...-1).

2. Vaccination period (up to 1 day):

   • Visit 1 (day 1, randomization, blood collection for serological examination, vaccination).

3. Follow-up period (up to 28(+2) days):

   • Visit 2 (day 3, organization of trials to assess safety);
   • Visit 3 (day 7(+1), organization of trials to assess safety);
   • Visit 4 (day 21(+2), organization of trials to assess safety, blood collection for serological study);
   • Visit 5 (day 28(+2), organization of trials to assess safety, trial completion);

Inclusion Criteria:

• Presence of signed informed consent to participate in the trial.
• Volunteers (both male and female) over the age of 60 who could meet the Protocol requirements.
• Negative pregnancy test obtained from female volunteers with preserved childbearing potential.
• Consent to use adequate contraception methods (contraception methods with degree of reliability of more than 90%: a nonhormonal intrauterine device; a spermicide condom; a spermicide cervical cap; spermicide diaphragms) or total sexual abstinence during the clinical trial (until Visit 5 (day 28(+2)).

Exclusion Criteria:

• Allergic reactions to chicken protein or any previous influenza vaccination.
• Anamnestic data on the episodes of severe allergic reactions and/or diseases (anaphylaxis, Quincke's edema, polymorphic exudative erythema, serum disease etc.)
• Acute reaction (temperature above 38.5оС, edema and hyperemia over 5 cm in diameter at the injection site) or complications caused by previous administration of the drug.
• Previous vaccination 6 months before the start of the trial.
• History of leucosis, blood cancer, malignant oncological diseases.
• Guillain-Barré syndrome (acute polyneuropathy) in the medical history.
• Positive screening for HIV infection, B and C hepatitis, syphilis.
• Any confirmed or suspected immunosuppressive or immunodeficiency condition;
• Administration of immunoglobulin or blood products within the last three months before the study.
• Long-term use (more than 14 days) of immunosuppressants (including systemic corticosteroids, cytotoxic, radioactive preparations) or other immunomodulatory drugs for six months before the trial.
• Chronic diseases at the decompensation stage or in debilitating form, which can make it dangerous for the volunteer to take part in the trial.
• Progressive neurological disorders, dementia.
• Blood disorders which serve as a contradiction for intramuscular injection.
• History of alcohol or drug addiction.
• Pregnancy, breastfeeding in women with preserved reproductive performance.
• Current participation in another clinical trial or within the previous 3 months before the screening.
• Mental, physical and other problems which do not allow for appropriate assessment of own behavior and following the requirements set out in the trial protocol.
• Any other conditions which in the reasonable opinion of the clinical investigator complicate the participation of the volunteer in the trial