The objectives of this study were to assess the safety and tolerability of DCB07010 when given intranasally at escalating dose levels of 7.5μg, 15μg, 30μg and 45μg, in combination with 22.5μg of influenza HA antigen (7.5μg HA of each of three strains) and to generate sufficient immunogenicity data to enable dose selection for larger and more definitive Phase 2 studies.

This was a single center, double-blind, randomized (2:1), dose-escalation study to assess the safety, tolerability and immunogenicity of 4 different vaccine-adjuvant doses in comparison to influenza HA alone. The 4 treatment cohorts were given DCB07010 in a dose- escalating manner.

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