Efficacy, Immunogenicity and Safety Study of GSK Biologicals' Candidate Malaria Vaccine (SB257049) Evaluating Various Dose Schedules in a Sporozoite Challenge Model in Healthy Malaria-naïve Adults

This study is designed to evaluate efficacy, immunogenicity and safety of various dose schedules of GSK Biologicals' candidate malaria vaccines RTS,S/AS01B (adult formulation) and RTS,S/AS01E (pediatric formulation) in healthy malaria-naïve subjects aged 18-55 years. The purpose of this study is to investigate whether changes in dosing schedule are associated with increased or equivalent protection, and to evaluate the immune mechanisms associated with vaccine efficacy under varying dosing schedules.