Immunoglobulin isotypes profiles, IgG1 and IgG2a, of anti-MSP1-19 antibodies from IL-4 KO, STAT6 KO and WT mice immunized with P30P2MSP1-19 in different adjuvant formulations. Panel A, QS21; Panel B, CFA/IFA; Panel C: MPL-AF; Panel D, MF59; Panel E, MPL-SE. Symbols: black bars, IgG1; light grey bars, IgG2a. Significant differences in the Ig isotype responses (Student t test) between the WT and KO mice of an adjuvant group are indicated by asterisks above the corresponding Ig isotype.