Clinical Trial: Investigating the Immunogenicity of a U.S.-Licensed Meningococcal Serogroup B Vaccine (Trumenba)

Study Status: Active, not recruiting
Recruit Status: Active, not recruiting
Study Type: Interventional

Official Title: Immunogenicity of a U.S.-Licensed Meningococcal Serogroup B Vaccine (Trumenba) in Adults at Increased Risk of Meningococcal Disease Because of Occupational Exposure

Brief Summary: This study will investigate the breadth of protection against meningococcal disease in humans immunized with a newly FDA approved meningococcal B vaccine, trade name "Trumenba®" manufactured by Pfizer Vaccines. As a secondary goal the investigators will investigate underlying mechanisms by which human anti-FHbp antibodies elicit complement-mediated bactericidal activity.

Detailed Summary: Neisseria meningitidis causes meningitis and severe infections of the blood stream. The incidence of serogroup B meningococcal disease however is too low to conduct a randomized, controlled trial to determine the actual efficacy of the new serogroup B vaccines. Instead vaccine efficacy was inferred from serum bactericidal antibody responses using four test strains. However, because of strain variability of FHbp amino acid sequence (there are more than 800 sequence variants described) and strain variability of FHbp expression, bactericidal data on only four strains are unlikely to be sufficient to predict the actual strain coverage by the vaccine. There also are gaps in knowledge about the underlying mechanisms by which human antibodies to FHbp elicit complement mediated bactericidal activity. For example, binding of FH to FHbp is specific for human FH. Therefore in vaccinated humans the vaccine antigen is expected to form a complex with FH right after immunization. The investigators' hypothesis is that binding of human FH to the vaccine antigen skews the antibody repertoire to FHbp epitopes located outside of the FH combining site. The resulting antibodies would be expected not to inhibit binding of FH to the bacteria. This hypothesis will be investigated in Trumenba-immunized humans as part of studies in Aim 1 (and in future studies of recombinant human anti-FHbp Fabs that will be enabled by obtaining DNA from individual B cells, described in Aim 2).
Sponsor: Children's Hospital & Research Center Oakland

Current Primary Outcome: Breadth of protective activity of serum anti-FHbp antibody responses of adults immunized with Trumenba vaccine as assessed by serum bactericidal titers [ Time Frame: 18 months ]

Determine the percentage of subjects achieving serum bactericidal titers of 1:4 or greater in serum obtained 1 month after doses 2 and 3 as measured against a panel of 15 genetically diverse meningococcal strains.


Original Primary Outcome: Same as current

Current Secondary Outcome: Antibody repertoire to FHbp [ Time Frame: 1 year ]

Determine the percentage of recombinant anti-FHbp Fabs isolated from B cells of each subject that react with 3 FHbp amino acid sequence variants representative of FHbp variant groups 1, 2 and 3


Original Secondary Outcome: Same as current

Information By: Children's Hospital & Research Center Oakland

Dates:
Date Received: September 30, 2015
Date Started: January 2015
Date Completion: May 2017
Last Updated: September 28, 2016
Last Verified: October 2015