Development of an effective malaria vaccine that could be deployed widely in endemic areas has proved to be more difficult than was anticipated, when the first clinical trials of malaria vaccines were conducted 30 years ago. Substantial progress has been made during the past few years and one candidate vaccine, RTS,S/AS02, shows promise. However, during the period that malaria vaccine development has been taking place, alternative methods of malaria control including insecticide treated bednets and intermittent preventive treatment in infancy and childhood have been developed and shown to be partially effective. Malaria vaccines will need to be more effective or more cost effective than these alternative control strategies or be able to provide substantial added value, when deployed with them if they are to be adopted widely.