Sporozoite malaria vaccine. Where do we stand?

A sporozoite malaria vaccine which elicits high levels of antibodies to the circumsporozoite (CS) protein may protect part of the human population in areas of low endemicity. Other possible targets of a sporozoite vaccine are the liver stages, but in this case the effector cells are T-lymphocytes which recognize sporozoite-derived peptides in association with products of the major histocompatibility complex. There is no evidence that the variation observed in the CS protein of P. falciparum is driven by immunological pressure, nor that this variation will be a major impediment to vaccine development.