From these U.S. total IgG and Mali total IgG pools, AMA1(3D7) or AMA1(FVO)-specific IgGs and non-AMA1(3D7) or non-AMA1(FVO) IgGs were prepared individually using AMA1(3D7) or AMA1(FVO) protein immobilized on Sepharose 4 Fast Flow columns as described previously [27] . During the affinity purification process for each total IgG, the flow-through fraction was reloaded to the same AMA1-immobilized column three times to increase the efficacy of separation. Both AMA1-specific IgGs and non-AMA1 IgGs were dialyzed against RPMI 1640 and concentrated to 150,300 ml (AMA1-specific IgGs) or 40 mg/ml (non-AMA1 IgGs) of final product. Because of the limitations of volumes available, AMA1(3D7)-specific/non-AMA1(3D7) IgGs were not prepared from D0-2 or D0-3 total IgG pools.