Cloning of EBV-immortalized IgG + B cells from 28 of the VSAPAM-specific lines by limiting dilution resulted in eight clones producing VSAPAM-specific IgG1. Lines were selected for cloning on the basis of their IgG synthesis Flow cytometry analysis of human VSA-specific plasma IgG reactivity with the surface of P. falciparum-IEs. Labelling of FCR3-CSA, NF54-VAR2CSA and 3D7-SM by IgG in individual plasma samples from P. falciparum-exposed pregnant women ( ), from sympatric men (᭢) and from non-exposed adult control donors (᭹) are shown. and growth characteristics. Six of the clones (PAM1.4, PAM2.8, PAM3.10, PAM5.2, PAM6.1, PAM7.5) produced antibodies recognizing antigens on the surface of erythrocytes infected by both the VSAPAM-expressing lines used to screen for antibody specificity (Table 1) . Antibodies from the two remaining clones (PAM4.7 and PAM8.1) only recognized FCR3-CSA. In contrast, none of the monoclonal antibodies recognized the 3D7-SM control line not expressing VSAPAM ( Fig. 2A-C) . Testing of monoclonal antibody reactivity with erythrocytes infected by a panel of additional parasite lines provided further evidence that all were indeed specific for PAM-type VSA expressed on the surface of CSA-adhering IEs (Table 1) . However, the monoclonal antibodies did not all recognize all VSAPAM-expressing lines, probably because the epitopes they recognize are polymorphic. IgG antibodies produced by a control B-cell clone (D7) did not recognize any of the tested parasite lines. Monoclonal antibody recognition patterns for individual parasite lines were tested in parallel, and repeated assessments of recognition patterns yielded consistent results.