Clinical Trial: Safety and Immune Response to an Investigational Dengue Type 2 Vaccine

Study Status: Completed
Recruit Status: Completed
Study Type: Interventional

Official Title: A Phase I Evaluation of the Safety and Immunogenicity of rDEN2/4 Δ30(ME) Dengue Serotype 2 Vaccine Given at 10^1 PFU in Healthy Flavivirus-naïve Adult Subjects

Brief Summary: Dengue viruses can cause dengue fever and other serious health conditions, primarily affecting people living in tropical regions of the world. This study will test whether a vaccine developed to prevent infection with dengue virus type 2 causes a response in people's immune system and is safe.

Detailed Summary:

Dengue viruses cause approximately 50 million cases of dengue fever and 1.5 million cases of the more severe diseases dengue hemorrhagic fever (DHS) and dengue shock syndrome (DSS) every year. There are four subtypes of the virus, and infection with one offers no protection from infection by the others. In fact, most cases of DHS and DSS occur in people infected by more than one subtype. In areas of the world where multiple subtypes of dengue are common, vaccines must be developed against each of the subtypes of dengue virus. This study will examine the safety and immune response of an investigational vaccine for preventing dengue virus type 2.

Participation in this study will last about 6 weeks. Participants will be randomly assigned to be injected with either the investigational study vaccine or a placebo. Participants will have a five in six chance of receiving the vaccine. The first study visit will take place on the vaccination day, on which participants will undergo a physical examination, blood draw, and pregnancy test and then receive the vaccine. Participants will be given a thermometer and temperature card and be told to record their temperatures three times per day for 16 days after vaccination. Participants will come to follow-up visits every other day for the 16 days after vaccination and then 3, 4, and 6 weeks after vaccination (Days 21, 28, and 42). Assessments completed during these visits will include a questionnaire about how the participant is feeling, pregnancy test, review of temperature cards, blood draw, and physical exam. Blood drawn will be analyzed to check participants' health, determine the amount of vaccine and antibodies in the blood, test markers in white blood cells and genes, and look for proteins that are important for fighting dengue infection.


Sponsor: National Institute of Allergy and Infectious Diseases (NIAID)

Current Primary Outcome:

  • Immunogenicity of vaccine, as assessed by neutralizing antibody titers [ Time Frame: Measured at 4 and 6 weeks after vaccination ]
  • Safety of vaccine, as assessed by the frequency of vaccine-related adverse events (AEs), graded by severity [ Time Frame: Measured throughout study ]
  • Number of vaccinees infected with this dengue virus subtype 2 (DEN2) candidate vaccine, as defined by either recovery of vaccine virus from the blood of vaccinated participants and/or by seroconversion to DEN2 [ Time Frame: Measured at Days 28 and 42 ]


Original Primary Outcome: Same as current

Current Secondary Outcome:

  • Frequency, quantity, and duration of viremia [ Time Frame: Measured after vaccination ]
  • Comparison of infectivity rates, safety, and immunogenicity of a single dose of DEN2 vaccine from this trial to those variables on previous trials [ Time Frame: Measured at study completion ]


Original Secondary Outcome: Same as current

Information By: National Institute of Allergy and Infectious Diseases (NIAID)

Dates:
Date Received: February 19, 2010
Date Started: February 2010
Date Completion:
Last Updated: December 31, 2012
Last Verified: December 2012