Anti-O:2 IgG (panel A) and Anti-CRM₁₉₇ (panel B) serum IgG ELISA units detected in sera of CD-1 mice immunized with O:2-conjugates and unconjugated O:2.

<p>Mice were immunized three times at two week-intervals with the indicated doses of material. Mice were bled and sera collected on the indicated days. Individual animals are represented by the scatter plots; bars represent the group geometric mean.