SAFLI-R21-10
SAFLI-R21-10 is an ancillary study conducted within the framework of the broader IMVACS project but under a stand-alone protocol separate from the main IMVACS study. This study is designed to compare the safety, reactogenicity, and humoral immunogenicity of the 10-dose (multidose) formulation of R-21/Matrix-M with 2-Phenoxyethanol (2-PE) preservative vs the safety, reactogenicity, and humoral immunogenicity of the 2-dose formulation of R21/Matrix-M vaccine.
The findings will inform the potential use of this formulation for booster administration in the main IMVACS trial, as well as its feasibility for large-scale deployment in malaria-endemic settings.
Sponsor: Serum Institute of India
Principal Investigator: Prof. Kassoum Kayentao (University of Sciences, Techniques and Technologies of Bamako – USTTB)
Study Location: Dioïla Health District, Mali
- Wacoro (Control Arm)
- Kola (Intervention Arm)
Study Duration: 8 months
Sample Size: 100 children in total. A sub-sample of the first 50 children eligible to receive R21/Matrix-M in the control arm (Group 1) and the first 50 children in the intervention arm (Group 2) of the IMVACS study will be enrolled in the SAFLI-R21-10 trial.
Group 1- Control Arm (Wacoro)
- Receives three doses of the 10-dose formulation with 2-PE, administered before the SMC campaign as in IMVACS control arm (pre-SMC vaccination)
- Dose administration:
- First dose: June 13–15, 2025
- Second dose: July 11–13, 2025
- Third dose: Four weeks after the second dose
Group 2 – Intervention Arm (Kola)
- Receives the three doses of 10-dose formulation with 2-PE, administered during the SMC campaign
- First dose: July 17, 2025 (during first round of SMC)
- Subsequent doses: in August and September, aligned with the SMC second and third rounds
Safety and reactogenicity assessment
Safety and reactogenicity data will be both actively and passively collected.
Indeed, after vaccination, Local and systemic solicited adverse events will be monitored over a 7- day follow-up period (day of vaccination and 6 subsequent days by home visits) after each vaccination while unsolicited adverse events will be recorded over a 28-days follow-up period (day of vaccination and 27 subsequent days) after each vaccination. Serious adverse events (SAEs) will be recorded for all the study participants for the duration of the study (from first dose to 28 days post dose 3).
Immunogenicity assessment
Vaccine immunogenicity for the 10-dose formulation with 2-PE will be assessed at baseline (pre-vaccination) and 28 days after the third priming dose. Antibody levels (overall and by trial arm) will be compared to those from children who received the 2-dose formulation in the main IMVACS trial. Specifically, immunogenicity data from a sub-sample of the first 50 children enrolled in both the control and intervention arms of the IMVACS trial—who received the 2-dose vial formulation—will be compared with data from children receiving the 10-dose formulation in the SAFLI-R21-10 trial.
