Clinical Trial: Expanded Characterization of Immune Response to Merck Adenovirus 5 Gag/Pol/Nef Vaccine Given to HIV Uninfected Adults

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

Official Title: A Phase 1B Open-label Clinical Trial to Expand the Characterization of the Immune Responses to the Merck Adenovirus Serotype 5 HIV-1 Gag/Pol/Nef Vaccine in Healthy, HIV-1-

Brief Summary: The purpose of this study is to intensively characterize the immune response, particularly the T-cell response, to a three-dose regimen of an adenovirus-based HIV-1 vaccine in HIV-uninfected adults.

Detailed Summary:

This study will look for relationships among the immune responses induced by MRKAd5 HIV-1 gag/pol/nef vaccine. The study will also determine if the T cells that respond to different vaccine epitopes have correspondingly different functional profiles. The study will evaluate the safety and tolerability of the vaccine regimen as well.

This study will last 60 weeks. All enrolled participants will receive vaccinations at Weeks 0, 4, and 26. There will be between 8 and 20 study visits including the screening visit, depending on the site location. A physical exam, interview, and blood collection will occur at most or all visits. All participants will undergo leukapheresis approximately 4 weeks after their last vaccination and at Week 52. Medical history, an HIV test, a pregnancy test, and HIV and risk reduction counseling will occur at selected visits. Additional blood collection is now occurring in this study to collect more information about the relationship between the immune response and efficacy to the vaccine.


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

Current Primary Outcome:

  • Relatedness of different immune response to vaccine [ Time Frame: Throughout study ]
  • Features and number of HIV-specific CD4 and CD8 T cells produced in response to the vaccine [ Time Frame: Throughout study ]
  • Characterization of different functions of T cells that have responded to the vaccine [ Time Frame: Throughout study ]
  • Safety and tolerability of three doses of vaccine [ Time Frame: Throughout study ]


Original Primary Outcome:

  • Relatedness of different immune response to vaccine, with the potential for application of the results to larger vaccine trials
  • The features and number of HIV-specific CD4 and CD8 T cells produced in response to the vaccine, as found by a technique called flow cytometry
  • Characterization of different functions of T cells that have responded to the vaccine
  • Safety and tolerability of three doses of vaccine given by injections in the muscle


Current Secondary Outcome:

  • Changes in physical features of certain immune cells in response to the vaccine [ Time Frame: Throughout study ]
  • Indications of an immune response to the vaccine [ Time Frame: Throughout study ]
  • Presence of T cells in the genital tract [ Time Frame: Throughout study ]


Original Secondary Outcome:

  • Changes in physical features of certain immune cells in response to the vaccine
  • Indications of an immune response to the vaccine by changes in the way some genes are expressed
  • Presence in the blood of small molecules called cytokines that indicate an immune response to the vaccine
  • Presence of T cells in the genital tract that are primed to respond specifically to HIV after injection of the vaccine into the muscle


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

Dates:
Date Received: June 12, 2007
Date Started: July 2007
Date Completion:
Last Updated: June 2, 2015
Last Verified: June 2015