Phase 1b Study Investigating Safety & Immunogenicity of TDV Given Intradermally by Needle or Needle-Free PharmaJet Injector

This is an exploratory trial to assess the safety, tolerability and immunogenicity of
vaccination with a tetravalent dengue vaccine (TDV) in healthy adults delivered intradermally
using the conventional needle/syringe or a needle-free PharmaJet® injector.

Two (2) intradermal injections of either vaccine or placebo will be administered to qualified
participants (one in each arm) on Day 0 of the study. A subsequent injection will also be
given on Day 90 with either vaccine or placebo (in one arm only).

Participants will be evaluated for safety and dengue neutralizing antibody to all four
serotypes. All participants will also be evaluated for injection site reactions and have
blood drawn for viremia, neutralizing antibodies, cell mediated immunity and innate immunity.

Participants will be required to participate for approximately 10 months from recruitment and
collection of data for primary outcomes (through Day 120) including collection of additional
samples for measurement of longer term antibody titers (through Day 270).

This project has been funded in whole or in part with Federal funds from the National
Institute of Allergy and Infectious Diseases, National Institutes of Health, Department of
Health and Human Services, under Contract No. HHSN272201000034C.

Inclusion Criteria:

- In good health as determined by medical history and physical examination (including
blood pressure and heart rate).

- Negative for human immunodeficiency virus-1 (HIV-1) antibodies, Hepatitis C antibodies
& Hepatitis B surface antigen.

- Females negative by urine pregnancy test at screening and immediately prior to
injection, and were willing to use reliable means of contraception.

- Body Mass Index (BMI) ≤ 35 kg/m^2.

Exclusion Criteria:

- Any Grade 2 or above abnormality in the screening laboratory tests.

- History of Dengue Fever, Japanese Encephalitis, West Nile or Yellow Fever disease.

- Seropositivity to dengue or West Nile virus.

- Extensive scarring or tattoo (> 50%) on arms, shoulders, neck face and head.

- History of significant dermatologic disease in the last 6 months.

- Receipt or planned receipt of any vaccine in the 4 weeks preceding or following the
Day 0 or 90 vaccinations.

- Any planned travel to dengue endemic areas including the Caribbean, Mexico, Central
America, South America or Southeast Asia, during the study period and during the month
prior to screening.

- Use of systemic corticosteroids therapy within the previous 6 months (at a dose of 0.5
mg/kg/day). Topical prednisone is not permitted if currently in use or used within the
last month prior to the first vaccination.

- Use of any prescribed medication 7 days before the first injection.

- Previous vaccination in a clinical study or with an approved product against Dengue
Fever, Yellow Fever and or Japanese Encephalitis.

- Known or suspected congenital or acquired immunodeficiency or receipt of
immunosuppressive therapy in the last 6 months.

- Planned donation of blood during the period of the study.