The general goal of the project is to assess the infectious status and immunity of mothers and children living in a malaria region. A major part of the study involves administering an effective antimalarial, sulfadoxine-pyrimethamine (Fansidar®), to children at the same timepoints as vaccinations, i.e. at age 3, 9 and 15 months. The main objective is to study safety, efficacy, and consequences of such a strategy in particular the ability to reduce the risk of anemia.