Fig. 2.

Immunoglobulin G (IgG) (a), IgM (b) and IgE (c) levels to crude Plasmodium falciparum antigen and the recombinant antigen C231, divided into different age groups, 4–9 years (n = 15), 10–14 years (n = 17), 15–19 years (n = 18) and 20–87 years (n = 50). Enzyme-linked immunosorbent assay using sera from Senegalese donors as described in Materials and methods measured antibody reactivity. The boxes represent the values between the 25% to the 75% quartile and the line indicates the median. The whiskers indicate the 10% and 90% quartile. *P < 0·05.