FIG. 3.

Long-term changes in levels of plasma antibodies recognizing PfEMP1-like molecules on the surface of intact RBC infected with late developmental stages of homologous and heterologous P. falciparum isolates as detected by flow cytometry. The reactivity of plasma from two individuals (P8 [left column] and P11 [right column]) with four parasite isolates collected in 1994 (S9457, top row), 1995 (Z453, second row; Z455, third row), and 1996 (Y372, bottom row) is shown. Isolates Z455 and Z453 were collected during clinical malaria attacks in November 1995 from individuals P8 and P11, respectively. Symbols are as in Fig. 2.