Binding of anti-rNspA and control MAbs to live encapsulated N. meningitidis serogroup B strains BZ198, 8047, and M986 as determined by indirect-fluorescence flow cytometry. The anti-NspA MAbs include AL4, AL5, AL11, and AL12. The control MAbs include a murine MAb with an irrelevant specificity (VIG10), an anticapsular-specific murine MAb (SEAM 12), and, for strains 8047 and M986, an N. meningitidis subtype MAb anti-PorA P1.2 (Rijksinstituut Voor Volksgezondheid en Mileu, Bilthoven, The Netherlands). A subtyping anti-PorA MAb was not available for strain BZ198.