FIG. 2.

Reactivity profiles of IgG antibodies detectable with rRAP1 proteins C1 (a), P3 (b), and P5 (c) in 499 serum samples donated by 53 individuals between 1991 and 1995. Each serum sample was tested by ELISA at a dilution of 1:500, and reactions were developed with peroxidase-conjugated rabbit anti-human IgG diluted 1:5,000. Cutoff levels (means + 2 standard deviations of 33 European serum samples) and the indicated range of OD values above the cutoffs were used to grade arbitrarily the strength of each reaction. □, below cutoff level; ▧, above cutoff (OD < 0.5); ▥, above cutoff (OD = 0.5 to 1.0); ■, above cutoff (OD > 1.0); #, clinical malaria infection with no available plasma sample; Conv, convalescence sample collected 30 to 40 days after clinical malaria infection.