Finding the best R21/Matrix-M booster dose for schoolchildren

A Phase II Randomised Trial to Evaluate the Safety and Immunogenicity of a R21/Matrix-M Booster Vaccine at Two Different Doses in Burkinabe School Children

This project will test whether a 5 µg or 10 µg R21/Matrix-M booster is safer and produces stronger immunity in school-aged children who previously received four doses.

Quick facts

• Phase: Phase 2
• Study type: Interventional
• Enrollment: 40 (estimated)
• Ages: 6 Years to 8 Years
• Sex: All
• Sponsor: University of Oxford (Academic / other)
• Locations: 1 site (Nanoro)
• Trial ID: NCT07074665 on ClinicalTrials.gov

What this trial studies

This is a double-blind, randomized Phase 2 trial enrolling 30–40 children from the earlier VAC 076 cohort in Nanoro, Burkina Faso. Participants who received four prior 5 µg R21/50 µg Matrix-M doses will be randomly assigned to receive either a 5 µg or 10 µg R21 booster with 50 µg Matrix-M. Safety events and antibody responses will be monitored closely after vaccination and participants will be followed for one year to measure durability of the immune response. The trial aims to identify a booster dose that balances tolerability with stronger, longer-lasting immunity in school-aged children.

Who should consider this trial

Good fit: Ideal candidates are school-aged children who received all four doses of 5 µg R21/50 µg Matrix-M in the VAC 076 study and who live in the Nanoro study area with parental consent.

Not a fit: Children who did not complete the original four-dose series, have a history of severe allergic reactions to vaccines, major congenital defects, active anemia with clinical signs, or who are enrolled in another malaria vaccine trial are unlikely to benefit or be eligible.

Why it matters

Potential benefit: If successful, the right booster dose could prolong protection against Plasmodium falciparum in school-aged children and inform dosing for wider use.

How similar studies have performed: Previous Phase IIb data from the R21/Matrix-M program, including the VAC 076 cohort, showed promising immunogenicity and protection, but booster dose optimization at school age is less well studied.

Eligibility criteria

Inclusion Criteria:

* The child received four doses of R21/Matrix-M in the phase IIb study evaluating R21/MatrixM in Nanoro, Burkina Faso (VAC 076).
* 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 is expected to remain a resident for the duration of the trial.

Exclusion Criteria:

* The child is enrolled in another malaria vaccine trial.
* The child has a history of allergic disease or reactions likely to be exacerbated by any component of the malaria vaccine.
* 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 ≤ 5.0 g/dL.
* 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.
* Children currently meeting the WHO criteria for HIV disease of stage 3 or 4 severity. A previous history of stage 3 or 4 disease is not an exclusion. Note: There will be no routine testing for HIV. Positive diagnoses will be recorded at screening if known.
* The child has received an investigational drug or investigational 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.

Where this trial is running

Nanoro

• Unité de Recherche Clinique de Nanoro (URCN) — Nanoro, Burkina Faso (Recruiting)

Study contacts

• Study coordinator: Mehreen Datoo

Conditions Malaria; Malaria Vaccine; R21/Matrix-M