Fig. 2.

Proposed model to explain the inter-relationships between antibodies, var expression and apparent parasite multiplication rate (PMR). a In the absence of αIE antibodies, parasites expressing a subset of “dominant” PfEMP1 with high intrinsic cytoadhesive capacity dominate the infection (black) because of their ability to limit splenic parasite clearance rate. b As a result, these variants will be the first to be recognized by the developing host antibody response. c The surviving parasites express PfEMP1 variants that can evade antibodies, but because they have a lower intrinsic cytoadhesive capacity, these parasites have a higher splenic clearance rate, resulting in a lower observed apparent PMR. The thick grey horizontal line represents the endothelial cells that make up the inner wall of microvessels. d under a model of variant specific immunity, dominant variants (orange shapes) may arise that are poorly recognised by antibodies carried by the host population (grey rectangles) allowing them to establish infections (arrows). Their expression levels would be correlated with growth rate but poorly correlated with bulk measures of pre-infection antibodies