The suggestion that active immunization may be of value in protection against malaria is not new. However, it has received very little attention during the last two decades mainly because of the development of satisfactory antimalarial drugs and of residual insecticides. But as Powell and Brewer point out in their paper, reports of increasing incidence of resistance of malaria parasites to chemotherapeutic agents and of mosquitoes to insecticides have once again directed attention to the study of alternative methods of protection against the disease. Recent investigations in the field of passive transfer of malaria immunity in animals and in man have raised hopes of the possibility of developing a suitable vaccine.
Powell and Brewer have raised many interesting and important issues relating to the nature of immunity in malaria, and they have pointed out some of the outstanding practical difficulties which must be resolved before the development of a useful vaccine can be realized.
Department of Chemical Pathology, University of Ibadan, Nigeria.