Vaccines to Accelerate Malaria Elimination and Eventual Eradication

Abstract

Remarkable progress has been made in coordinated malaria control efforts with substantial reductions in malaria-associated deaths and morbidity achieved through mass administration of drugs and vector control measures including distribution of long-lasting insecticide-impregnated bednets and indoor residual spraying. However, emerging resistance poses a significant threat to the sustainability of these interventions. In this light, the malaria research community has been charged with the development of a highly efficacious vaccine to complement existing malaria elimination measures. As the past 40 years of investment in this goal attests, this is no small feat. The malaria parasite is a highly complex organism, exquisitely adapted for survival under hostile conditions within human and mosquito hosts. Here we review current vaccine strategies to accelerate elimination and the potential for novel and innovative approaches to vaccine design through a better understanding of the host-parasite interaction.

Figure 1.

Points of intervention of a malaria vaccine to accelerate toward elimination. (A) Within-host malaria parasite population dynamics showing bottlenecks post–mosquito injection and after uptake of the blood meal where the parasite is vulnerable to vaccine-induced immune mechanisms. (B) Vaccine-targetable processes within the Plasmodium life cycle. Areas susceptible to antibody-mediated mechanisms are shown in yellow and cell-mediated mechanisms in blue. This schematic does not account for the exoerythrocytic hypnozoite stage causing relapsing blood-stage Plasmodium vivax infections. RBC, Red blood cell; SPZ, sporozoite.