A Phase 2, Double-blind Study to Evaluate Intranasal Trivalent Influenza Virus Vaccine in Healthy Adult

Inclusion Criteria: * Adult male and female subjects aged between 20-70 (included) years. * Should be physically and mentally healthy and free of significant medical condition as determined by Medical history, Physical examination and Clinical judgment of the Investigator. * Negative urine β-human chorionic gonadotropin in women of childbearing potential (WOCBP; defined as women ≤ 50 years old of age or history of amenorrhea for ≤12 months) prior to administration of first dose of Investigational Product. * WOCBP and male subjects having female partners, who are WOCBP, should be protected by effective contraceptive method (e.g. oral contraceptive and condom, intra- uterine device and condom, diaphragm with spermicide and condom) throughout the study period. * Willing and able to give written informed consent prior to Screening and comply with study procedure. Exclusion Criteria: * Received vaccination against influenza within 6 months prior to Screening. * Received any vaccination (other than influenza) within 28 days prior to Screening. * Has previously experienced anaphylaxis or a life-threatening reaction; or has history of allergy or hypersensitivity to egg proteins, chicken proteins, any of the components of Investigational Product, or other vaccine containing same substances. * History of influenza infection (confirmed either clinically, serologically or microbiologically) within the 6 months prior to administration of first dose of Investigational Product. * Had active allergic rhinitis within 28 days prior to administration of first dose of Investigational Product. * Has documented history of diarrhea within 28 days prior to administration of first dose of Investigational Product. * Have used or been administered any intranasal medication or nasal topical treatment within 7 days prior to Screening. * Acute respiratory illness within 7 days prior to administration of first dose of Investigational Product. * Had administration of systemic antibiotics or antivirals within 7 days prior to Screening (excluding topical/external use of antibiotics). * Acute sinusitis or chronic sinusitis accompanying acute symptoms within 3 days prior to administration of first dose of Investigational Product. * With acute disease (defined as fever with body temperature \>38.0°C), within 3 days prior to administration of first dose of Investigational Product. * Having any serious chronic illness, including but not limited to, cardiovascular, pulmonary, hepatic, metabolic, renal or any auto-immune disorders, at a stage that could interfere with trial conduct or completion. * Any confirmed or suspected immunosuppressive or immune-deficient condition, based on medical history and physical examination. * Documented history of Bell's palsy or neurological disorder. * Receive aspirin (Salicylate) anytime in the study from screening (Visit 1) * A positive test for HIV antibody * Receipt of any immunoglobulins and/or blood products within 3 months of study Screening. * Pregnant or breast-feeding women * Require extended long-term use of steroids including parenteral steroids or high dose inhaled steroids or have used within 28 days prior to Screening * Participated in any other clinical investigation or use of any investigational therapy other than AD07030, within 4 weeks (28 days) or 5 half-lives, whichever is longer, before Screening. * Unable to communicate reliably with the Investigator or unlikely to cooperate with the requirements of the study procedures or schedule, or other cases judged by the Investigator to be ineligible for participation in the study. * Other cases judged by the Investigator to be ineligible for participation in the study.