Study to Assess Efficacy of New Malaria Vaccine Candidates AdCh63 AMA1, MVA AMA1, AdCh63 MSP1, MVA MSP1, AdCh63 ME-TRAP & MVA ME-TRAP

This study aims to test the safety and efficacy of six new malaria vaccines - AdCh63 AMA1, MVA AMA1, AdCh63 MSP1, MVA MSP1, AdCh63 ME-TRAP \& MVA ME-TRAP. These vaccines consist of inactivated viruses which have been modified - so they cannot reproduce (replicate) in humans, and also to include genetic material (genes) for malaria proteins which are expressed by the malaria parasite during both liver and blood stage infection. The vaccines are designed to stimulate an immune response to these malaria proteins (immunogenicity describes the nature and magnitude of this immune response) and thus provide protection against malaria infection. The protective efficacy of vaccines will be evaluated by challenging a small number of volunteers who have received the vaccines with malaria infection from the bites of infected mosquitos(sporozoite challenge).