Double-blind Study of Safety and Immunogenicity of Two Candidate Malaria Vaccines in Gabonese Children

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.