RTS,S/AS02 and the quest of the Holy Grail

High-profile programs under the WHO/Roll Back Malaria initiative, in addition to unravelling the human and malaria parasite genomes, have ensured that malaria vaccine research and development are enjoying an unprecedented boom. So far, the development of a vaccine against such a complex parasite has been elusive. Recently, there have also been concerns that imperfect vaccines could encourage the selection of more virulent parasite strains [1]. However, there is compelling evidence that, if an effective malaria vaccine was developed, it would prove to be protective because several studies have shown that: (1) immunity to malaria can develop of multiple Plasmodium infection; and (2) exposure to bites from irradiated Anopheles infected with Plasmodium falciparum can confer protection against infection for up to 10 months. Based on these findings, effector T-cell vaccines that rate pre-erythrocytic stages of the parasite in infected hepatocytes have been developed.