Anti-malaria MAb in Kenyan Children

Inclusion Criteria Healthy children aged 5 months to 10 years (Part 1) or 5-59 months (Part 2). Weight ≥5 kg and weight ≤30 kg (Part 1) or weight ≥5 kg and ≤22.5 kg (Part 2) or weight ≥5 kg and ≤20 kg (for 30 mg/kg group) or weight ≥5 kg and ≤15 kg (for 40 mg/kg group), to ensure a maximum volume of two 2-mL (Part 1b) Hemoglobin level ≥8 g/dL. Height and weight Z-scores \>-2. Living within Alego-Usonga sub-county. Able to participate for the duration of the trial. Parent and/or guardian of participant able to provide informed consent. Exclusion Criteria Individuals meeting any of the following criteria will be excluded from study participation: Taking long-term cotrimoxazole. Participation or planned participation in any other interventional trial with an investigational product prior to the last required protocol visit or receipt of an investigational product within the past 30 days. (Note: Past, current, or planned participation in observational studies is NOT exclusionary.) Received any doses of any malaria vaccine. Participation in part 1 of this study (for individuals being screened for enrollment into part 2) Age \< 12 months at the time the RTS,S/AS01 vaccine is anticipated to become available in the whole of Siaya County Current significant medical condition (neurologic, cardiac, pulmonary, hepatic, endocrine, rheumatologic, autoimmune, renal, oncologic, or hematological) or evidence of any serious underlying medical condition identified by medical history, physical examination, or laboratory examination. Known sickle cell disease. (Note: Known sickle cell trait is NOT exclusionary.) White blood cell, absolute neutrophil, or platelet count outside the local laboratory-defined limits of normal. Subjects may be included at the investigator's discretion for values that are not clinically significant (ie., do not require any repeat or follow-up). Alanine transaminase (ALT) or creatinine (Cr) level above the local laboratory-defined upper limit of normal. (Subjects may be included at the investigator's discretion for values that are not clinically significant.) Infected with HIV. History of a severe allergic reaction or anaphylaxis. Severe asthma (defined as asthma that is unstable or required emergency care, urgent care, hospitalization, or intubation during the past 2 years, or that has required the use of oral or parenteral corticosteroids at any time during the past 2 years). Pre-existing autoimmune or antibody-mediated diseases including but not limited to: systemic lupus erythematosus, rheumatoid arthritis, multiple sclerosis, Sjogren's syndrome, or autoimmune thrombocytopenia. Known immunodeficiency syndrome. Use of chronic (≥14 days) oral or IV corticosteroids (excluding topical or nasal) at immunosuppressive doses (i.e., prednisone \>10 mg/day) or immunosuppressive drugs within 30 days of day 0. Known asplenia or functional asplenia. Clinical signs of malnutrition. Receipt of immunoglobulins and/or blood products within the past 6 months. Any history of menses. Behavioral, cognitive, or psychiatric disease that in the opinion of the investigator affects the ability of the subject to understand and comply with the study protocol. Parental/guardian study comprehension examination score of \<80% correct or per investigator discretion. Receipt of a live vaccine or a killed vaccine within the past 2 weeks prior to study agent administration. Known allergies or contraindication to dihydroartemisinin-piperaquine. Use or known need at the time of pre-enrolment (DP administration) of concomitant prohibited medication, including: Antimicrobial agents of the following classes (systemic use only): Macrolides (e.g. erythromycin, clarithromycin, azithromycin, roxithromycin) Fluoroquinolones (e.g., levofloxacin, moxifloxacin, sparfloxacin) Pentamidine Antiarrhythmic agents (e.g. amiodarone, sotalol) Antihistamines (e.g. promethazine) Antifungals (systemic): ketoconazole, fluconazole, itraconazole Antiretrovirals: Saquinavir Diuretics (e.g. hydrochlorothiazide, furosemide) Antipsychotics (neuroleptics): haloperidol, thioridazine Antidepressants: imipramine, citalopram, escitalopram Antiemetics: domperidone, chlorpromazine, ondansetron Increased risk of salivary gland hypofunction (dryness of the mouth, swelling under the tongue and/or below the ear, halitosis) History of any other illness or condition which, in the investigator's judgment, may substantially increase the risk associated with the subject's participation in the protocol or compromise the scientific objectives, or other condition(s) that, in the opinion of the investigator, would jeopardize the safety or rights of a subject participating in the trial, interfere with the evaluation of the study objectives, or render the subject unable to comply with the protocol.