This study will test the safety of an experimental vaccine for preventing West Nile virus infection. The virus is spread mainly by mosquito bites. Symptoms can include high fever, headache, neck stiffness, stupor, muscle weakness, vision loss, numbness and paralysis. Rarely, infection leads to permanent nerve damage and possibly death. The vaccine used in the study is made from DNA that codes for West Nile virus proteins. Injected into a muscle, the DNA instructs the body to make a small amount of West Nile virus protein. This study will see if the body creates resistance or immunity to these proteins. Participants cannot get West Nile virus from the vaccine.
Healthy normal volunteers between 18 and 65 years of age may be eligible for this study. Candidates are screened with a medical history, physical examination, and blood and urine tests for various infections and other medical problems. Women who are able to become pregnant are given a pregnancy test. Women who are pregnant or breastfeeding may not participate. Anyone who has received a vaccination for Yellow Fever or Japanese Encephalitis virus in the past may not participate in this research study.
Participants will receive three injections of the experimental vaccine, the first on the first study day (Day 0), the second on Day 28, and the third on Day 56. The injections are given with a device called Biojector® (Registered Trademark) 2000 that delivers the vaccine through the skin into the muscle without the use of a needle. On the day of each injection, subjects are given a diary card to take home for recording their temperature and any symptoms or side effects for 5 days. They return to the clinic 2 weeks after each injection, bringing the completed card with them at that time. In addition to the injections, subjects have the following tests and procedures during clinic visits:
Medical history and, if needed, physical examination: Day 0 and weeks 2, 4, 6, 8, 10, 12, 24 and 32
Vital signs and weight: Day 0 and weeks 2, 4, 6, 8, 10, 12, 24 and 32
Lymph node exam: Day 0 and weeks 2, 4, 6, 8, 10, and 12
Blood samples: Day 0 and weeks 2, 4, 6, 8, 10, 12, 24 and 32
Pregnancy test (for women): Day 0 and weeks 4, 8 and 32
Urine sample: Day 0 and weeks 2, 4, 6, 8, and 10
The blood and urine tests are for health checks. Some blood samples are also used to study the immune response to the vaccine and for gene testing.