Inclusion Criteria at study entry:  Age:  Group 1: The child is 5-11 months of age at the time of randomization (i.e. up to the day before of their first birthday). Group 2: The child is 12-23 months of age at the time of randomization (i.e. up to the day before of their second birthday). Group 3: The child is 24-36 months of age at the time of randomization (i.e. up to the day of their third birthday). Group 4: The child is 6-7 months of age at the time of randomization. Group 5: The child is 6 weeks of age at the time of randomization and have not received any dose of the pentavalent vaccine and only the first dose of the OPV. Group 6: The child is aged 5-36 months at the time of their first vaccination Signed informed consent/thumb-printed and witnessed informed consent obtained from the parent(s)/guardian(s) of the child to join the trial. The investigator believes that the parents/guardians can and will comply with the requirements of the protocol if the child is enrolled in the study. The child is a permanent resident of the study area and likely to remain a resident for the duration of the trial.  Exclusion Criteria at study entry:  The child has previously received a malaria vaccine. The child is enrolled in another malaria intervention trial that could interfere with the results of this study. The child has a history of allergic disease or reactions likely to be exacerbated by any component of the study vaccines. The child has a history of allergic reactions, significant IgE-mediated events or anaphylaxis to previous immunisations. The child has major congenital defects. The child has anaemia associated with clinical signs of symptoms of decompensation, or a haemoglobin of ≤7.4 g/dL. The child has had a blood transfusion within one month of enrolment. The child has been administered immunoglobulins and/or any blood products within the three months preceding the planned administration of the vaccine candidate. The child has malnutrition requiring hospital admission. The child has an acute or chronic, clinically significant pulmonary, cardiovascular, gastrointestinal, endocrine, neurological, skin, hepatic or renal functional abnormality, as determined by medical history, physical examination or laboratory tests. Any confirmed or suspected immunosuppressive or immunodeficient state, including HIV or asplenia. The child has received an investigational drug or vaccine other than the study vaccines within 30 days preceding the first dose of study vaccine, or planned use during the study period. The child is currently participating in another clinical trial if likely to affect data interpretation of this trial The child has any significant disease, disorder or situation which, in the opinion of the Investigator, may either put the participants at risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial. Clinically significant laboratory abnormality as judged by the study clinician For group 5 only: the child has received any dose of the pentavalent vaccine or has received more than one dose of the OPV.  Exclusion criteria during the study (to be checked prior to each vaccination):  • Any significant disease, disorder or situation which, in the opinion of the Investigator, may either put the participants at risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial.