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.
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).
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
OTHER
Masking
NONE
Enrollment
18
All subjects will receive three doses of a Trumenba, a U.S.-licensed meningococcal vaccine. Each 0.5 mL dose contains 60 micrograms of each FHbp variant (total of 120 micrograms of protein), 0.018 mg of PS80 and 0.25 mg of Al³+ as AlPO4 in 10 mM histidine buffered saline at pH 6.0. Trumenba is administered as a three dose series (0.5 mL each) according to a 0-, 2-, and 6-month schedule.
UCSF Benioff Children's Hospital Oakland
Oakland, California, United States
University of Massachusetts Medical School
Worcester, Massachusetts, United States
Breadth of Protective Activity of Serum Anti-FHbp Antibody Responses of Adults Immunized With Trumenba Vaccine as Assessed by Serum Bactericidal Titers
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.
Time frame: 18 months
Antibody Repertoire to FHbp
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
Time frame: 1 year
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