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Infant Malaria Vaccine Schedule Optimization

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

Status
Recruiting
Phases
Phase 2
Study type
Interventional
Source
PACTR
Registry ID
PACTR202411825510335
Enrollment
964
Registered
2024-11-14
Start date
2025-03-03
Completion date
Unknown
Last updated
2026-06-22

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Malaria

Interventions

Normal saline

Sponsors

PATH
Lead Sponsor

Eligibility

Sex/Gender
All

Inclusion criteria

Inclusion criteria: • Signed informed consent or thumb-printed and witnessed informed consent obtained from the parent/legal guardian of the infant. - Infants must have been born full-term (at =37 weeks of gestation) and > 2500 grams at birth. -Immunization schedule Cohorts 1, 2, and 3: : Male and female infants 42-49 days (inclusive) of age at time of enrollment. For infants in Cohort 1, randomization to receive vaccine dose 1 (Groups 1 and 2 of R21/MM or placebo, respectively) will occur at 42-49 days of age. For infants in Cohort 2, randomization to receive vaccine dose 1 (Groups 3 and 4 of R21/MM or placebo, respectively) will occur at 2 months (56-63 days of age). For infants in Cohort 3, randomization to receive vaccine dose 1 (Groups 5 and 6 of R21/MM or placebo, respectively) will occur at 3 months (84-91 days of age). - The participant’s parent/guardian must be willing to avoid travel, particularly in the 28 days after each study vaccination, must confirm willingness to contact the study team in the event of unexpected/unavoidable travel and, for the safety cohort, must confirm availability for the home visits to be conducted by a field worker to collect solicited AEs over the 7 days (day of vaccination and 6 subsequent days) following each study vaccine. - The participant’s parent/guardian must confirm willingness to bring their child to the study clinic / local health care clinic, and capacity to contact the study team in the event the subject has any illnesses or other health concerns during the study. - Participants who the investigator believes that their parent/guardian can and will comply with the requirements of the protocol (e.g. return for follow-up visits) may be enrolled in the study.

Exclusion criteria

Exclusion criteria: -Acute disease at the time of enrolment (acute disease is defined as the presence of a moderate or severe illness with or without fever). This does not include minor illnesses such as diarrhea, mild upper respiratory infection, without low-grade febrile illness, i.e. axillary temperature < 37.5°C or tympanic temperature < 38°C. (Note: In case of acute disease, participants may be re-assessed by a study physician for resolution of the condition and enrolled if eligible and still within the visit window). -Clinically significant pulmonary, cardiovascular, gastrointestinal, endocrine, neurological, skin, hepatic or renal functional abnormality, as determined by medical history, physical examination or laboratory tests 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. -At time of enrollment, any infant who has received any dose of the hexavalent/pentavalent vaccines, pneumococcal vaccine, rotavirus vaccine, IPV or has received more than one dose of oral polio virus or more than one dose of hepatitis B vaccine. -Weight-for-length/height Z score of less than -3 or other clinical signs of malnutrition. -Infant with major congenital defects. -The infant has anaemia associated with clinical signs of symptoms of decompensation, or a haemoglobin of = 5.0 g/dL. -History of allergic disease or reactions likely to be exacerbated by any component of the vaccines. -Any confirmed or suspected immunosuppressive or immunodeficient state (including HIV or asplenia) or known maternal HIV infection (no HIV testing will be routinely done by the study team). -Administration of immunoglobulins and/or any blood products/blood transfusion from birth to time of planned administration of the vaccine candidate. -Previous vaccination of participant or biological mother with a malaria vaccine. -Participation in another research study involving receipt of an investigational product

Design outcomes

Primary

MeasureTime frame
1.Geometric mean titers (GMTs) of anti-CS NANP IgG at baseline and 28 days after 3rd vaccine dose for each immunization schedule category. 2.Ratio of anti-CS NANP GMTs 28 days after R21/MM 3rd vaccine dose for infants in i) 3-6-9 month to 2-4-6 month schedule; ii) 3-6-9 month to 6- 10-14 week schedule; iii) 2-4-6 month to 6-10-14 week schedule. 3.Geometric mean fold rise (GMFR) in anti-CS NANP IgG 28 days after 3rd vaccine dose compared to baseline anti-CS NANP concentrations in each immunization schedule category. ;1.Local (redness, swelling, and pain at the injection site) and Systemic (fever, drowsiness, irritability, decreased appetite) reactions. 2.Unsolicited Adverse events (AEs) 3.Serious adverse events (SAEs) 4.Adverse Events of Special Interest (AESI)

Secondary

MeasureTime frame
1. Geometric mean titers (GMTs) of anti-CS IgG before and 28 days after 4th vaccine dose in the “compressed” and “relaxed” immunization schedule categories. 2. Ratio of anti-CS GMTs 28 days after 4th R21/MM vaccine dose for infants in i) 3-6-9 month to 2-4-6 month schedule; ii) 3-6-9 month to 6-10-14 week schedule; iii) 2-4-6 month to 6-10-14 week schedule. 3. Geometric mean fold rise (GMFR) in anti-CS titer post 4th dose compared to pre-4th dose for the “compressed” and “relaxed” immunization schedule categories.

Countries

Burkina Faso

Contacts

Public ContactMichael;Michael Thigpen;Thigpen

Senior Medical Officer Clinical Functional Area Path;Senior Medical Officer Clinical Functional Area Path

mthigpen@path.org;mthigpen@path.org+12028220033;+12028220033

Outcome results

None listed

Source: PACTR (via WHO ICTRP) · Data processed: Jun 28, 2026