Dose-Escalating Study of Pfs230D1 in Combination With R21 in Matrix-M in African Adults

Inclusion Criteria: 1. Age: 18 to 50 years old. 2. Provides written informed consent. 3. Able to understand and comply with planned study procedures and be available for the duration of the trial. 4. In good general health and without clinically significant medical history in the opinion of the investigator. 5. Females of childbearing potential must be willing to use reliable contraception from 21 days prior to Study Day 1 and until 1 month after the last vaccination. Exclusion Criteria: 1. Pregnant and breastfeeding females. 2. Hemoglobin, white blood cell (WBC), absolute neutrophil count, or platelet levels outside the local laboratory-defined reference ranges. 3. Alanine transaminase (ALT) or creatinine (Cr) level above the local laboratory-defined upper limit of reference range. 4. Infected with HIV, hepatitis B, hepatitis C. 5. Evidence of clinically significant neurologic, cardiac, pulmonary, hepatic, endocrine, rheumatologic, autoimmune, hematological, oncologic, or renal disease by history, physical examination, and/or laboratory studies. 6. Current or planned participation in an investigational product study until the time period of the last required study visit under this protocol. 7. Medical, occupational, or family problems as a result of alcohol or illicit drug use during the past 12 months. 8. History of a severe allergic reaction or anaphylaxis. 9. Known: Severe asthma, Autoimmune or antibody-mediated disease, Immunodeficiency, Seizure disorder, Asplenia or functional asplenia, Use of chronic oral or intravenous corticosteroids (excluding topical or nasal), Sickle cell disease. 10. Any other condition that in the opinion of the investigator might jeopardize the safety or rights of a subject participating in the trial, interfere with the evaluation of the study objectives, or might render the subject unable to comply with the protocol.