Acquisition of immune response against D and C regions of MSP2 occurs early in life in malaria-exposed donors. Sera from children of different ages (1–5 years old) living in Tanzania were collected and used in direct ELISA. A) Shows age dependent recognition of 3D7-D and its 20 mers peptides (N: number total of children = 186). B) Shows age dependent recognition of different LSPs representing P27A (MR252; N = 208), exported protein 1, EXP1 (MR127B; N = 254) and CS (MR48A, MR48; N = 254). Sera were used at dilution of 1/200.