Clinical Trial: Safety and Immunogenicity Study of ChimeriVax West Nile Vaccine in Healthy Adults

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

Official Title: Randomized, Modified, Double-blind, Placebo-controlled, Phase II, Dose-ranging Study of the Safety and Immunogenicity of Single Dose ChimeriVax-WN02 Vaccine in Healthy Adults.

Brief Summary: The purpose of this study is to determine if ChimeriVax West Nile vaccine is safe and effective in preventing West Nile disease in adults over 50 years of age.

Detailed Summary: Currently, the only method of prevention of West Nile infection is control of the mosquito vectors associated or avoidance of mosquito bites, which has proven largely ineffective. Developing a safe, effective vaccine and making it widely available will enhance the prospects of prevention and control of this disease. In addition, natural infections with the YF virus and WN virus are more severe in the elderly. Therefore, a study among healthy older subjects or those with well controlled chronic diseases will provide data to determine a ChimeriVax-WN02 vaccine dose that is immunogenic and well tolerated.
Sponsor: Sanofi Pasteur, a Sanofi Company

Current Primary Outcome:

  • Geometric Mean Titers (GMTs) of Antibodies to Vaccination With ChimeriVax™ WN02 or a Placebo Vaccine [ Time Frame: Day 0 and Day 28 post-vaccination ]
    Antibodies to the vaccine antigens were measured by the Plaque Reduction Neutralization Test.
  • Number of Participants With Seroconversion Following Vaccination With ChimeriVax™ WN02 or a Placebo Vaccine. [ Time Frame: Day 0 and Day 28 post-vaccination ]

    Antibodies to vaccine were measured by the Plaque Reduction Neutralization Test.

    Seroconversion was defined as a four-fold or greater rise in titer between pre- and post-injection samples; or a post-vaccination (Day 28) titers of ≥ 1:20 in participants with baseline titer ≤ 1:10.

  • Number of Participants Reporting Solicited Injection Site or Systemic Reactions Following Vaccination With ChimeriVax™ WN02 or a Placebo Vaccine. [ Time Frame: Day 0 up to Day 14 post-vaccination ]


Original Primary Outcome: To evaluate the safety and immunogenicity of ChimeriVax-WN02 vaccine at three different dose levels. [ Time Frame: within first 28 days ]

Current Secondary Outcome: Number of Participants Developing Viremia After Vaccination With ChimeriVax™ WN02 or a Placebo Vaccine. [ Time Frame: Day 2 up to Day 14 post-vaccination ]

Viremia is defined as number of subjects in the analysis population dose group with detected (≥ 20 Plaque forming units [pfu]/mL) viremia at the reported visit.


Original Secondary Outcome: To compare the potential vaccine viremia induced by three different dose levels of ChimeriVax-WN02 vaccine. [ Time Frame: within the first 14 days ]

Information By: Sanofi

Dates:
Date Received: September 2, 2008
Date Started: October 2008
Date Completion:
Last Updated: March 17, 2015
Last Verified: March 2015