A Trial of a Walter Reed Army Institute of Research (WRAIR) Live Attenuated Virus Tetravalent Dengue Vaccine in Healthy US Adults

Subjects will be randomized into one of 6 groups. One group will receive a placebo vaccine
and the others will receive one of 5 different dengue vaccine formations. Each subject will
receive two doses six months apart. Study subjects who elect to participate in a mosquito
transmissibility component of the study will undergo mosquito feedings during each of the two
assigned follow-up visits after vaccine dose 1. All subjects will have 11 venipunctures
during 11 visits (i.e., screening plus 10 study visits) over a period of nine months.

Inclusion:

- Healthy male or female adult 18-45 years at the time of vaccination

- Free of obvious health problems as established by medical history and physical
examination before entering into the study

- Written informed consent obtained from the subject

- Able to read the Subject Information Sheet and Consent Form

- Subjects who the investigator believes can and will comply with the requirements of
the protocol

- Females must be of non-childbearing potential, or, if of childbearing potential, she
must be abstinent or have used adequate contraceptive precautions as defined in the
protocol for 30 days prior to vaccination, have a negative pregnancy test within 48
hours prior to vaccination and must agree to continue such precautions for 60 days
after completion of the vaccination series

Exclusion:

History of:

- recurrent migraine headache

- any neurological or behavioral disorder or seizures

- drug abuse or alcohol consumption (more than 2 drinks per day)

- allergic disease/reaction likely to be exacerbated by vaccine

- urticaria related to mosquito bites requiring medical attention

- Acute or chronic, clinically significant pulmonary, cardiovascular, hepatic, renal,
hematologic or endocrine functional defect

- Any confirmed or suspected immunosuppressive or immunodeficient condition;

- Seropositive for HBsAg, anti-HCV or anti-HIV

- Acute disease at the time of enrollment

- Chronic hepatomegaly or splenomegaly

- Use of any investigational or non-registered drug or vaccine within 30 days preceding
study or planned use

- Planned administration of a vaccine not foreseen by the study protocol 30 days ±each
vaccine dose

- Planned move during study

- Chronic administration (defined as more than 14 days) of immunosuppressants or other
immune-modifying drugs or administration of immunoglobulins and/or blood products,
within 90 days preceding the first dose or planned administration during the study
period

- Any chronic systemic drug therapy to be continued during the study period