Fig. 1
Serum bactericidal antibody (SBA) titres in sera of mice immunised with human adenovirus encoding N-terminal signal sequence variants of the factor H binding protein. Groups of six BALB/c mice were immunised with a sub-optimal dose of 1 × 107 infectious units of one of the signal sequence variant constructs or 1/10 of the human dose of 4CMenB (two-dose regimen administered at day 0 and day 21) and SBA assays were performed against the H44/76 strain of Neisseria meningitidis using sera derived from blood samples taken at different timepoints post-immunisation. A Week two SBA titres. B Week four SBA titres. C Week six SBA titres. The dotted red line represents the cut-off titre of 1:4 deemed sufficient for protection. Differences in the SBA titre between constructs are attributable to the N-terminal signal sequence variants of the factor H binding protein, particularly at early timepoints post-immunisation. Statistical comparisons were made using a Mann–Whitney U-test. *p < 0.05; **p < 0.01