FIG 2.

Bactericidal activity of antisera from mice immunized with individual antigens. Data are shown for one representative isolate from each of the university outbreaks (CH819 and CH840; Table 2) and four control strains (Table 1), each matched for only one of the four antigens in MenB-4C reported to elicit bactericidal activity: H44/76 (FHbp), 5/99 (NadA), M4407 (NHba), and SK016 (PorA P1.4) (Table 1). *, the dilution of the anti-PorA P1.4 MAb that killed strain SK016 is arbitrary; the strain was killed by <0.4 μg/ml. The outbreak strains from university A and university B were killed only by the anti-FHbp antiserum. The data are reported as the means ± ranges of the results from two independent experiments. Similar results were obtained with two other tested outbreak isolates, CH827 and CH838 (from universities A and B, respectively; data not shown). The dotted line represents values of <1:10, the lowest dilution tested.