Integrating Malaria Vaccine With Seasonal Malaria Chemoprevention in West Africa

Malaria incidence among children aged 5-36 months over 24 and 36 months

Malaria incidence among children aged 5-36 months over 24 and 36 months post first dose using routine surveillance activities for clinical malaria detection and reporting;

Time frame: From enrollment to 2 years after booster

Malaria incidence among children aged 3-59 months over 24 and 36 months

Malaria incidence among children aged 3-59 months over 24 and 36 months post first dose using routine surveillance activities for clinical malaria detection and reporting

Time frame: From enrollment to 2 years after booster

Malaria prevalence at peak transmission

Malaria prevalence at peak transmission in November after SMC campaigns in 2025 and 2026

Time frame: From enrollment to 2 years after booster dose

Vaccine coverage

Pourcentage of children who has received 3 or 4 doses at 24 months post 1st vaccination

Time frame: From enrollment to months 24

Occurrence of adverse events (AEs) and serious adverse events (SAEs) following R21/Matrix-M vaccination;

Occurrence of adverse events (AEs) and serious adverse events (SAEs) following R21/Matrix-M vaccination

Time frame: From enrollment to months 4

Acceptability

Qualitative interviews and FGDs among policy makers, health managers, health providers and caregivers

Time frame: From 12 months after study start to 36 months

Stakeholder perceptions of the feasibility on the vaccine delivery strategy in each group

Acceptability and feasibility studies will use qualitative longitudinal study (QLS) research methods. We will apply an ecological framework approach with emphasis on the interplay and inter-dependency between individual, interpersonal, organizational, and policy levels. Qualitative data will be collected through ethnographic immersion, in-depth interviews, group interviews and focus group discussions. No quantitative measurements will be made.

Time frame: From enrollment to months 36

Contextual and behavioural factors impeding or facilitating R21/Matrix-M vaccine uptake

Interviews and FGD - will be explained in a parallel protocol

Time frame: From enrollment to months 24

Stakeholders and caregivers perceptions of the factors that enhance and/or constrain the succesful co,pletion of four doses of R21 and the key drivers of vaccination coverage

The study will cover a full, two-year R21/Matrix-M delivery cycle with data collection at two time points in each arm: soon after the primary series is delivered, and soon after the booster dose is provided a year later. This longitudinal approach will enable us to explore and chart dynamic processes as they occur, barriers and facilitators, and acceptability over time. It is inherently suitable for studying R21/Matrix-M introduction, requiring prolonged and repeated involvement by patients and providers. This approach is also necessary to explore the drivers of vaccine hesitancy which is not a static state; vaccine decision-making changes over time as caregivers experience different influences and nudges along the way. Qualitative data will be collected through ethnographic immersion, in-depth interviews, group interviews and focus group discussions to explore factors in the service delivery, household, and broader social environments that will lead to R21 adoption and adherence. A

Time frame: From enrollment to months 24 and 36

Incremental costs (per child vaccinated) and cost-effectiveness (per malaria case and separately, per DALY averted) of each vaccination strategy, calculated from a societal perspective

Costs associated with the different vaccination strategies will be estimated by collecting data on direct and indirect costs to health systems and opportunity costs to vaccinees and their caregivers (beneficiaries). Beneficiary costs will be collected during household surveys, via case report forms developed to collect data on direct costs (transport, food, medication) and indirect costs (time and income loss) incurred by their household related to each intervention arm. Provider costs will be collected using custom built spreadsheets structured to comprehensively capture the resources used for all intervention delivery related activities (excluding research activities) by cost category (person time, equipment, consumables including vaccines, storage, transport, overheads and other costs) by arm. Malaria incidence estimates (primary clinical outcome) will be used to calculate malaria cases and DALYs averted by arm, adjusted for intervention coverage (using the coverage survey data).

Time frame: From enrollment to months 36