Walsh & Hoyt: Prevention

Most malaria control strategies rely on insecticides, either spraying areas or using insecticide-impregnated bed nets, against the vector and antimalarial drugs as prophylaxis or treatment. Although these strategies are reasonably effective, the emergence of resistance in both vectors and parasites emphasizes the need for an affordable and effective malaria vaccine. Valero et al. reported the results of a randomized, double-blind, placebo-controlled efficacy trial in Colombia that tested the safety and immunogenicity of a chemically synthesized vaccine, SPf66, directed against P. falciparum. Over 1500 volunteers received either placebo or vaccine. Active and passive case-detection methods were used to document clinical attacks of malaria among the study population over a follow-up period of 1 year. The results of this study suggest that this vaccine is safe, immunogenic, and protective against malaria caused by P. falciparum. A follow-up field trial in Thailand is under way with SPf66 as the next step in eventual licensure of the vaccine in Europe and the United States. Additional vaccines are under development.