The study is Multicenter, phase 3, Open-Label trial that explored the preventive effectiveness, safety and immunogenicity of single dose a allantoic split inactivated seasonal influenza vaccine in healthy adults.

The study will include 2000 volunteers, 1,000 of whom will be vaccinated intramuscularly with a single dose of allantoic split inactivated seasonal influenza vaccine.

All participants will be observed for 6 months to evaluate the effectiveness of the vaccine.

Inclusion Criteria:

• Healthy volunteers of both sexes aged from 18 years.
• Literate and willing to provide written informed consent.
• A signed informed consent.
• Able to attend all scheduled visits and to comply with all trial procedures.

Exclusion Criteria:

• Allergic reactions to chicken proteins, or any preceding vaccination.
• Acute illness with a fever (37.0 C).
• Vaccination against influenza in the 2017/2018 season.
• Current or recent (within two weeks of enrollment) acute respiratory illness with or without fever.
• Hypersensitivity after previous administration of any vaccine.
• History of chronic alcohol abuse and/or illegal drug use.
• A positive pregnancy test for all women of childbearing potential.
• Administration of immunosuppressive drugs or other immune modifying drugs within 4 weeks prior to study enrollment.
• Acute or chronic clinically significant pulmonary disease, cardiovascular disease, gastrointestinal disease, liver disease, neurological illness, liver disease, blood disease, skin disorder, endocrine disorder, neurological illness and psychiatric disorder as determined by medical history, physical examination or clinical laboratory screening tests, which in the opinion of the investigator, might interfere with the study objectives.
• History of leukemia or any other blood or solid organ cancer.
• Receipt of antivirals, antibiotics, immunoglobulins or other blood products within 4 weeks prior to study enrollment or planned receipt of such products during the period of subject participation in the study.
• Participation in another clinical trial within the previous three months or planned enrollment in such a trial during the period of this study.
• Subjects who are, in the opinion of the investigator, at significantly increased risk of non-cooperation with requirements of the study protocol.