Scientists seek to block pathogen’s most reliable weapon to cause severe malaria The parasites that cause severe malaria are well-known for the sinister ways they infect humans, but new research may lead to drugs that could block one of their most reliable weapons: interference with the immune response. In the study, scientists defined the atomic-level architecture of the connection between a protein on the surface of a parasite-infected red blood cell when it binds to a receptor on the surface of an immune cell. When that protein-receptor connection is made under normal circumstances, the infected red blood cell, hijacked by the disease-causing parasite, de-activates the immune cell - meaning the body won't fight the infection. A drug designed to fit into that space could block the interaction, allowing the immune system to get to work clearing away the pathogen.