This study evaluates the immunogenicity and safety of 'IL-YANG Quadrivalent Influenza Vaccine Inj.' in healthy male and female adults at the age of 19 or older.

In this study, only eligible subjects for the study based on the inclusion/exclusion criteria will be randomized to the following stratification groups by age to receive one dose of the test vaccine, comparator 1, or comparator 2.

• Group A: healthy adults at the age of ≥ 19 and < 65.
• Group B: healthy adults at the age of ≥ 65.

During the study participation, the investigator will assess immunogenicity and safety in subjects. The investigator will perform immunogenicity tests at Visits 1 and 3 (end of study visit) for immunogenicity evaluation (prior to the investigational product vaccination) and instruct subjects to record AEs occurring after the investigational product vaccination for safety assessment.

A blood sample will be collected from a subject who is assigned a subject number. Following an intramuscular injection of 0.5mL investigational product in the deltoid muscle of the shoulder, the subject will have a study visit on Week 4 for blood sampling for antibody titer testing. In addition, a telephone visit will be performed to assess serious AEs (SAEs) up to Day 180 after vaccination.

Inclusion Criteria:

• Healthy men and women at the age of 19 or older.
• Women of childbearing potential must have a negative pregnancy test (urine HCG) at the screening visit.
• Subjects who were given, and fully understood, the information about the study, and have provided voluntary written informed consent to participate in the study and to comply with all applicable study requirements.

Exclusion Criteria:

• Subjects with known allergy to eggs, chicken, or any components of the study vaccine.

• Subjects who had received an influenza vaccine within the last 6 months prior to study entry.

• Subjects who have immune function disorders including immunodeficiency diseases or relevant family history.

• Subjects who donated blood within 1 week prior to vaccination or plan to donate blood during the period from Day 1 to Month 7 of vaccination.

• Subjects with a history of Guillain-Barre syndrome.

• Subjects with Down's syndrome or cytogenetic disorders.

• Subjects who are considered by the investigator to have difficulties in study participation due to severe chronic diseases (e.g., cardiovascular diseases except controlled hypertension and respiratory diseases with respiratory failure, metabolic diseases, renal function disorders, hemoglobinopathy, etc.).

• Subjects with hemophilia or coagulation disorder, who are at increased risk of serious bleeding during intramuscular injection.

• Subjects who had an acute fever with body temperature > 38.0 ºC within 72 hours prior to administration of the study vaccine.

• Subjects who had received another vaccine within 28 days before administration of the study vaccine or are planning to receive another vaccine during the study.

• Subjects who had received immunosuppressants or immune modifying drugs within 3 months prior to the investigational product vaccination.

  1. Azathioprine, cyclosporin, interferon, G-CSF, tacrolimus, everolimus, sirolimus, etc.
  2. High dose corticosteroids (a subject taking high doses, which is defined as 2mg/kg/day or higher of prednisolone administered for longer than 14 consecutive days, is not eligible for this study. The use of inhaled, nasal and topical corticosteroids is allowed, regardless of doses).

• Subjects who had previously received immunoglobulin or blood-derived products within the last 3 months prior to administration of the study vaccine, or are scheduled to receive a treatment with blood-derived products during the study.

• Subjects who had participated in another clinical trial within the 30 days before administration of the study vaccine.

• Female subjects of childbearing potential who do not agree to use an acceptable method of birth control* for this study during the study period.

  • Medically acceptable methods of birth control: condom, injectable or implantable contraceptives, intrauterine device, or oral contraceptives, etc.

• Subjects with other clinically significant medical or psychiatric illness who in the investigator's opinion, are not be suitable for the study.

Safety set consists of all randomized subjects who had at least one dose of the investigational product. A subject who was randomized in this study but was withdrawn prior to vaccination of the investigational product was excluded from the safety set. There was 3-subject withdrawn prior to vaccination from 1197 enrolled subjects.