Plasmodium vivax Malaria can cause severe illness in people. The parasite is thought to stick to tissues and organs resulting in disease. P. vivax is a chronic infection resulting in low levels of parasites in blood for a long time. One reason for this is that the parasite avoids the host?s antibody response. The malaria parasite lives for much of its life in red blood cells (RBC), and should be invisible to host antibodies. However, the parasite needs to communicate with the environment outside the RBC, and therefore produces molecules present on the RBC surface for this. This means that the parasite is no longer invisible and can be eliminated by antibodies. To avoid this, the proteins at the RBC surface constantly change by switching on and off genes that code for different variants, so that the parasite stays one step ahead of the antibody response. We will use a mouse model of malaria to investigate how the expression of these proteins is regulated, whether they are recognized by antibodies, and whether they are responsible for adhesion in organs. It might possible to use this knowledge to prevent adhesion and thus disease, and to develop vaccines.