Study of the Safety, Tolerability and Immunogenicity of an Intranasal Influenza Vaccine Administered to Healthy Adults

Inclusion Criteria:

1. Non-smoking adult aged between 20-40 years old;
2. Physically and mentally healthy subjects as confirmed by an interview, medical history, clinical examination, chest X-rays, ophthalmoscopy, cardiac echo, and electrocardiogram;
3. Body Mass Index (BMI) between 18.5 and 25, inclusive, (BMI will be calculated as weight in kilogram [kg]/height in meters2 [m2]);
4. Normal hematology, biochemistry and urinalysis determinations;
5. Subject is willing and able to comply with study procedures and sign informed consent

Exclusion Criteria:

1. Subject with serious underlying chronic illness;
2. Documented evidence of allergic rhinitis;
3. Subject with acute sinusitis or chronic sinusitis accompanying acute symptoms within 3 days prior to enrollment;
4. Immunosuppressed subjects as result of illness or treatment;

5. Female subject of childbearing potential who:

   • is lactating; or
   • has positive urine pregnancy test at Visit 2 or Visit 3; or
   • refuse to adopt reliable method of contraception during the study;
6. Subject received blood products or immunoglobulin within 3 months prior enrollment;
7. Subjects with long-term use of steroids, including parenteral steroids or high dose inhaled steroids within 28 days prior to enrollment;
8. Subject has received any intranasal medication or nasal topical treatment within 7 days prior to enrollment;
9. Subject has received any investigational agent within 28 days or 5 half- lives, whichever is longer, prior to the first dose of investigational product;
10. Subject has previously experienced anaphylaxis;
11. Subject has allergy to eggs or prior influenza vaccine;
12. Subject with laboratory-confirmed influenza or has been vaccinated against influenza within 6 months prior to enrollment;
13. Subject with acute respiratory illness or administered antibiotics or antivirals within 7 days prior to enrollment;
14. Subject with body temperature high than 38°C within 3 days prior to enrollment;
15. Subject with documented history of Bell's palsy or neurological disorder.
16. Subject with documented history of diarrhea within one month prior to study enrollment
17. A positive test for HIV antibody.
18. Subject has received Chinese medication or herbal medication within 28 days prior to enrollment