ABSTRACT
Malaria, caused by Plasmodium falciparum, Plasmodium vivax, Plasmodium malariae, or Plasmodium ovale, is a major health problem in most countries in the tropics. For years, it has been estimated that more than 2 billion people live in countries where malaria is transmitted, that there may be 300-500 million new infections and 1-3 million deaths annually caused by malaria, and that the majority of cases and more than 90% of the deaths occur in sub-Saharan Africa, where malaria is, in many places, the leading cause of death among children less than 5 years of age. Recent analyses suggest that the medical impact of malaria may actually have been significantly underestimated [1], and that the enormous economic impact of malaria has never been adequately considered [2]. It has been estimated that malaria reduces annual gross domestic product (GDP) in affected countries in sub-Saharan Africa by more than 1.3% [2]. As we begin the twenty-first century, it is troubling that a treatable infectious disease has such an “intolerable” impact. Yet, the increasing resistance of the Plasmodium sp. parasite to chemoprophylactic and chemotherapeutic agents, the resistance of the Anopheles sp. mosquito vector to insecticides, including the pyrethroids used in insecticideimpregnated bed-nets, and the inability of the most affected countries to mobilize and sustain the resources required for malaria control, as evidenced by the resurgence of malaria in areas formerly free of the disease, highlight the urgency for developing an effective malaria vaccine. A vaccine would dramatically improve the chances of optimally controlling, and eventually eradicating, malaria.
