A Study to Evaluate the Safety and Immunogenicity of GSK Biologicals' Candidate Vaccines RTS,S/AS02D (0.5 mL Dose) and RTS,S/AS02A (0.25 mL Dose) Administered IM According to a 0, 1, 2 Month Vaccination Schedule in Children Aged 3 to 5 Years Living in a Malaria-endemic Region of Mozambique.

Children participating in this study will either receive RTS,S/AS02D (0.5 ml dose) or RTS,S/AS02A (0.25 ml dose) intramuscularly according to 0, 1, 2 months schedule. The children will be followed-up throughout the study period to record safety events. Blood samples will be collected at defined time points to assess the subject's immune response to the relevant immunological indicators.

Inclusion criteria

Healthy children of both sexes between the ages of 3 to 5 years (up to but not including 6th birthday) who had not previously been immunized with hepatitis B vaccine, whose parents or guardians the investigator believed could and would comply with the requirements of the protocol, whose parents or guardians would give written or oral, signed or thumb printed and witnessed informed consent, who were free of obvious health problems as established by medical history and clinical examination before entering into the study and who were available for the foreseen duration of the immunization and follow-up period.

Exclusion criteria

If the child was found to have major congenital defects or serious chronic illness; history of surgical splenectomy; a diagnosis or clinical suspicion of an immunosuppressive or immunodeficient condition; family history of congenital or hereditary immunodeficiency; history of allergic disease or reactions likely to be exacerbated by any component of the vaccine; previous vaccination with hepatitis B vaccines or with an experimental vaccine; or if the child is simultaneously participating in any other clinical trial, then the child would be excluded from the study.