Mud-brick, thatch-roofed school houses in small villages that cling to rugged mountainsides in Papua New Guinea - this was the topic of conversation between two malaria researchers at a Philadelphia restaurant during a break in the action at the 2003 American Society of Tropical Hygiene meeting. Well, not the school houses themselves, but what was in them: A group of children who appear to be immune to the Plasmodium vivax parasite, despite their constant exposure. Why?












