Geometric mean titres. GMT of anti-CSP IgG antibodies in sera obtained from mice (n = 5) immunized at days 14, 35, 49 and 55 with 5 µg of DBL1x-DBL2x-ID2a:CSP (filled circles) or CSP-SpyCatcher (open triangles) formulated in aluminium hydroxide. Analyzed sera were obtained on days 14, 35, 49 and 55, respectively. The geometric mean titer of sera obtained on day 35 and 55 from the DBL1x-DBL2x-ID2a:CSP vaccination group (n = 5) was more than 1.9-fold higher than in sera obtained at the same time points from the CSP-SpyCatcher vaccination group. P-values based on Mann-Whitney Rank sum test were P=0.20 and P=0.27, respectively.