Research in Africa has found a one-time dose of an experimental drug protected adults against malaria for at least six months. The drug is a lab-made antibody. It works by breaking the life cycle of the parasite that causes malaria, which is spreads through mosquito bites. The antibody targets the parasites before they enter the liver where they can mature and multiply. The strategy may be an important complement to malaria vaccines. The new research was published Monday in the New England Journal of Medicine and presented at a medical meeting in Seattle.