We began with the affinity purification of AMA1-specific and non-AMA1 IgGs in order to evaluate the growth-inhibitory activity of the AMA1-specific fractions and to assess the possibility of interfering antibodies in the non-AMA1 IgGs from the Malian children. The antibody levels of each total IgG pool and non-AMA1(3D7)/AMA1(FVO) IgG were measured by ELISA and the results are shown in Table 1 . The non-AMA1 IgGs had less than 10% of AMA1 antibody levels compared to the corresponding original total IgG pools. These results showed that the AMA1specific purification method used in this study was efficient.