Enterohemorrhagic Escherichia coli (EHEC) produces Stx1 and Stx2 causing severe diseases. Their B-subunits (StxBs) exhibit low immunogenicity and the anti-StxB antibodies neutralizing both Stxs has not been prepared yet. By intranasal vaccination with His-tagged-StxB (Stx1B-His or Stx2B-His) plus a mutant heat-labile enterotoxin (mLT) in mice, their serum and lung fluid reacted with appropriate StxB. Mice vaccinated with Stx2B-His plus mLT had antibodies reacting Stx1B and showed the resistance to toxemia of Stx1 and Stx2. This is the first demonstration to get anti-Stx2B serum neutralizing both Stxs. These suggest that the nasal vaccination with Stx2B-His and mLT is effective for preventing toxemias by EHEC.