NCT06879327

Infant Malaria Vaccine Schedule Optimization

A Phase 2b Multicenter Randomized, Placebo-Controlled, Double-Blind, Study to Evaluate the Safety, Immunogenicity and Efficacy of R21/Matrix-M Malaria Vaccine in African Infants With Different Immunization Schedules

• Status: Recruiting
• Phase: Phase 2
• Study type: Interventional
• Enrollment: 1,200 (estimated)
• Sponsor: PATH · Academic / Other
• Sex: All
• Age: 42 Days – 49 Days
• Healthy volunteers: Accepted

Summary

The aim of this study is to identify an optimal infant vaccine schedule for a malaria vaccine which is better aligned with the timing of other vaccine interventions.

Detailed description

The R21/Matrix-M (R21/MM) vaccine has been recommended by the World Health Organization (WHO) to prevent clinical malaria in young children living in moderate to high transmission areas of Sub-Saharan Africa. R21/MM is based on the circumsporozoite protein (CSP) targeting the pre-erythrocytic stage of Plasmodium falciparum. R21/MM elicits high levels of antibodies against the central repeat (Asn-Ala-Asn-Pro \[NANP\]) of the circumsporozoite protein (CSP) which has been shown to correlate with protection. Currently, R21/MM is recommended to be delivered to young children starting at 5-6 months of age with 3 doses given at monthly intervals, however, there are no existing Essential Programme on Immunization (EPI) vaccine visits scheduled at these ages. We plan to evaluate, using the R21/MM malaria vaccine as a model system, how age at first vaccine dose and time intervals between doses modify the immunogenicity of the vaccine and the ensuant efficacy in protecting infants against clinical Plasmodium falciparum malaria. Healthy male or female infants 6 to 7 weeks of age will be randomized to one of three different immunization schedule cohorts: a) a "compressed" conventional schedule at 6-10-14 weeks of age; b) a "relaxed" schedule at 2-4-6 months of age; c) a "relaxed" schedule at 3-6-9 months of age. Participants in each immunization schedule cohort will be randomized in a ratio of 3:1 to receive 4 doses of either R21/MM or placebo with a 4th dose to be administered at 15 months of age. Infants randomized to the respective immunization schedule categories will receive co-administered routine EPI vaccines. The study will include the provision of a three dose R21/MM compressed schedule to all participants randomized to the placebo arms upon completion of the study at Month 27 of life.

Conditions

• Malaria Vaccines

Interventions

Type	Name	Description
BIOLOGICAL	R21 Matrix-M (R21/MM) Malaria Vaccine	Administered by intramuscular injection. Each 0.5 mL dose contains R21 Malaria Antigen (5 mcg) and Matrix-M1 (Adjuvant) (50 mcg).
BIOLOGICAL	Placebo	Administered by intramuscular injection. Each dose (0.5 mL) contains Normal saline (0.9%).
BIOLOGICAL	Hexavalent Vaccine	Administered by intramuscular injection. Each dose of 0.5 mL contains: * Diphtheria Toxoid \> 30 IU * Tetanus Toxoid \> 40 IU * B. pertussis (whole cell) \> 4 IU * Hepatitis B surface antigen (HBsAg) (recombinant DNA) 15 mcg * Inactivated polio vaccine (Salk strains grown on vero cells): Type - 1 (Mahoney strain) 40 D antigen units (DU); Type - 2 (MEF-1 strain) 8 DU; Type - 3 (Saukett strain) 32 DU * Haemophilus influenzae Type b (Hib) Conjugate Vaccine (Adsorbed) polyribosylribitol phosphate (PRP) 10 mcg conjugated to tetanus toxoid (TT) (carrier protein) 19 to 33 mcg\]
BIOLOGICAL	Pneumococcal Polysaccharide Conjugate Vaccine	Administered by intramuscular injection. Each 0.5 mL dose contains 2 mcg each Saccharide for serotypes 1, 5, 9V, 14, 19A, 19F, 23F, 7F, 6A and 4 mcg Saccharide for serotype 6B.
BIOLOGICAL	Rotavirus, Live Attenuated (Oral) Vaccine	Administered orally. Each 2.0 mL dose contains: Live Attenuated Bovine-Human Rotavirus Reassortant \[G1, G2, G3, G4 and G9\], 5.6 focus-forming units (FFU) / serotype.
BIOLOGICAL	Measles and Rubella Vaccine	Administered by subcutaneous injection. Each 0.5 mL dose contains not less than 1000 cell culture infectious dose 50% (CCID50) of Measles virus and 1000 CCID50 of Rubella virus.
BIOLOGICAL	Meningococcal A conjugate vaccine	Administered by intramuscular injection. Each 0.5 mL dose contains Meningococcal A polysaccharide 10 mcg and tetanus toxoid (TT) (carrier protein) 10 to 33 mcg.
BIOLOGICAL	Yellow Fever vaccine	Yellow fever vaccine will be locally sourced by each trial site in accordance with the countries' EPI program.
BIOLOGICAL	Typhoid Conjugate vaccine	Typhoid conjugate vaccine will be locally sourced by each trial site in accordance with the countries' EPI program.

Timeline

• Start date: 2025-05-30
• Primary completion: 2028-03-22
• Completion: 2028-03-22
• First posted: 2025-03-17
• Last updated: 2025-08-03

Locations

2 sites across 1 country: Burkina Faso