FACS analysis of N. meningitidis strains using sera prepared against vaccine antigens. (a) Binding of polyclonal antiserum raised against the individual antigens GNA2132, GNA1030, GNA2091, GNA1870, and NadA (left to right) to live encapsulated MenB strains NZ98/254 (first row), 2996 (second row), and MC58 (third row). The fourth row contains the MC58 knockout mutants (KO) of each antigen probed with the homologous antiserum. Red profiles represent the negative control (preimmune sera). White profiles show reaction with immune sera. (b and c) Binding of polyclonal antibodies against fusion proteins (b) and 5VCMB vaccine (c). First row, NZ98/254 (B:4:P1.4), ST cpx 41/44, ET lin.3, nadA−. Second row, 2996 (B:2b:P1.5,2), ST cpx 8, ET A4. Third row, MC58 (B:15:P1.7,16b), ST cpx 32, ET ET5.