Inclusion criteria:

• A male or female child between 18 months and 4 years of age (up to but not including 5th birthday) at the time of first vaccination.
• Written or oral, signed or thumb-printed and witnessed informed consent obtained from the parent(s)/guardian(s) of the child.
• Subjects who the investigator believes that their parents/guardians can and will comply with the requirements of the protocol (e.g. return for follow-up visits)

Exclusion criteria:

• Acute disease at the time of enrolment.
• Serious acute or chronic illness determined by clinical or physical examination and laboratory screening tests.
• Laboratory screening tests for haemoglobin, total white cell count, platelets, ALT and creatinine out of range.
• Planned administration/administration of a vaccine not foreseen by the study protocol within 30 days of the first dose of vaccine(s) with the exception of tetanus toxoid.
• Use of any investigational or non-registered drug or vaccine within 30 days preceding the first dose of study vaccine, or planned use during the study period.
• Administration of immunoglobulins, blood transfusions or other blood products within the three months preceding the first dose of study vaccine or planned administration during the study period.
• Chronic administration of immunosuppressants or other immune-modifying drugs within six months prior to the first vaccine dose.
• Previous participation in any other malaria vaccine trial.
• Simultaneous participation in any other clinical trial.
• Same sex twin.
• History of allergic reactions (significant IgE-mediated events) or anaphylaxis to previous immunizations.
• History of allergic disease or reactions likely to be exacerbated by any component of the vaccine.
• Any other findings that the investigator feels would increase the risk of having an adverse outcome from participation in the trial.