Evaluation of the Safety and the Ability of a DNA Vaccine to Protect Against Dengue Disease

Arguably the need for a tetravalent dengue vaccine that will effectively induce immunity against all four dengue serotypes has never been greater. Currently, several different approaches are being taken to develop a protective tetravalent dengue vaccine. These include live-attenuated vaccines derived by serial passage in tissue culture, live chimeric vaccines, recombinant protein vaccines and DNA vaccines. While live attenuated and live chimeric vaccines have shown promise in clinical trials, viral competition with suspected immune interference resulting in imbalanced immune responses and reactogenicity with the occurrence of dengue like symptoms remains a concern. It is imperative that any candidate vaccine produce solid immunity against each of the four dengue virus serotypes. Failure to do so may place the recipient of the vaccine at risk for developing severe dengue disease (dengue hemorrhagic fever/dengue shock syndrome) following exposure to the virus serotype to which there was incomplete protective immunity, resulting in antibody dependent enhancement due to the presence of non-neutralizing anti-dengue antibodies.

Inclusion criteria

• Male or female age 18 to 50 (inclusive) years old at the time of enrollment
• Have negative anti-dengue, Japanese encephalitis, West Nile, and yellow fever ELISA serological tests
• Be informed of the nature of the study and provide written informed consent
• If the subject is of child-producing potential, he/she agrees to practice adequate birth control or abstain from sex
• Have access to the WRAIR Clinical Trials for at least 270 days, and be willing to refrain from participation in other investigational clinical trials
• Be in good general health

Exclusion criteria

-Subjects meeting any of the following criteria will be excluded from the study:

• History of Flavivirus infection or history of Flavivirus vaccine (experimental or licensed product) including Japanese encephalitis, yellow fever, and dengue
• Have a known or suspected hypersensitivity or adverse reaction to vaccines including anaphylaxis and related symptoms such as hives, respiratory difficulty, angioedema, and/or abdominal pain
• Have received a live-attenuated vaccine within 42 days prior to the initial injection on Day 0 or a subunit or killed vaccine within 30 days of the initial injection on Day 0
• Have a positive screen for hepatitis B surface antigen (HBsAg), hepatitis C antibody, or HIV antibody
• Are pregnant or breastfeeding
• Have donated or received blood, blood products, or plasma within 30 days prior to Day 0
• Have any acute illness, including an oral body temperature >100.4°F, within 7 days before the initial injection on Day 0
• Have a past or current history of malignant disease except for adequately treated skin cancer
• Exclusions include but are not limited to conditions pertaining to or evidence of immunodeficiency; allergies requiring treatment with antigen injections; autoimmune disease; severe migraine headaches; unstable asthma; clinically significant cardiac arrhythmias, diabetes mellitus, thyroid disease, a bleeding disorder or a seizure disorder.
• Have participated in an investigational drug, vaccine, or device study within a period of 30 days prior to Day 0;
• History of splenectomy
• Planned travel to dengue endemic areas during the study period